阅读说明：本技术 电源设备、产生输出电压的方法和计算机可读存储硬件 (Power supply apparatus, method of generating output voltage, and computer-readable storage hardware ) 是由 锺柏荣 马丁·克吕格尔 于 2020-03-11 设计创作，主要内容包括：公开了一种电源设备、从电压转换器产生输出电压的方法和计算机可读存储硬件。该电源设备包括电压转换器、主控制器和偏置控制器。电压转换器包括初级和次级。控制器可操作成基于接收到的反馈信号来控制对来自次级的输出电压的调节。如其名称所表明的,来自次级的输出电压为负载供电。在某些负载状况期间,偏置控制器(通过新颖的偏置)保持电源电压的幅值高于偏置阈值。更具体地,偏置控制器可操作成防止电源电压降到偏置阈值以下,以防止欠压锁定状况,使得当负载增加对由输出电压提供的功率的消耗率时,控制器能够快速地继续从初级到次级的足够能量的传送。(A power supply apparatus, a method of generating an output voltage from a voltage converter, and computer readable storage hardware are disclosed. The power supply apparatus includes a voltage converter, a main controller, and a bias controller. The voltage converter includes a primary and a secondary. The controller is operable to control regulation of the output voltage from the secondary based on the received feedback signal. As its name suggests, the output voltage from the secondary powers the load. During certain load conditions, the bias controller (through the novel bias) maintains the magnitude of the supply voltage above the bias threshold. More specifically, the bias controller is operable to prevent the supply voltage from falling below the bias threshold to prevent an under-voltage lockout condition, such that the controller can quickly continue the transfer of sufficient energy from the primary to the secondary as the load increases the rate of consumption of power provided by the output voltage.)

1. A power supply apparatus comprising:

a voltage converter comprising a primary and a secondary;

a primary controller powered by a supply voltage, the primary controller operable to control regulation of an output voltage from the secondary based on a feedback voltage signal, the output voltage being output from the secondary to power a load; and

a bias controller operable to maintain a magnitude of the supply voltage above a bias threshold.

2. The power supply apparatus of claim 1, wherein the primary comprises a primary winding and an auxiliary winding, the auxiliary winding operable to generate the supply voltage; and is

Wherein during a first mode in which the load consumes power above a consumption threshold level, the magnitude of the supply voltage is operable to track the magnitude of the output voltage.

3. The power supply apparatus of claim 2 wherein during a second mode in which the load consumes power from the output voltage below the consumption threshold level, the bias controller is operable to bias the supply voltage to maintain the magnitude of the supply voltage above the bias threshold, the bias threshold being a minimum bias threshold.

4. The power supply apparatus of claim 1, wherein the bias controller comprises a comparator operable to:

comparing the magnitude of the supply voltage to the bias threshold; and

the bias controller is operable to activate a switching circuit in the primary in response to detecting that the magnitude of the supply voltage is at or below the bias threshold, activation of the switching circuit increasing the magnitude of the supply voltage above the bias threshold.

5. The power supply apparatus of claim 4, wherein the bias controller is further operable to deactivate the switching circuit in the primary after activating the switching circuit for a predetermined amount of time.

6. The power supply apparatus according to claim 1, wherein the bias threshold is a minimum bias threshold; and is

Wherein maintaining the supply voltage between the minimum bias threshold and the maximum bias threshold has a negligible effect on increasing the magnitude of the output voltage from the secondary.

7. The power supply apparatus of claim 4, wherein the comparator is further operable to:

comparing the magnitude of the supply voltage to a maximum bias threshold; and

the bias controller is operable to deactivate the switching circuit in the primary in response to detecting that the magnitude of the supply voltage is equal to or greater than the maximum bias threshold.

8. The power supply apparatus according to claim 1, wherein the bias threshold is a minimum bias threshold; and is

Wherein the bias controller is operable to control a duration of activation of a switching circuit in the primary, which transfers energy from the primary to the secondary, such that a magnitude of the supply voltage is maintained less than a maximum bias threshold.

9. The power supply device of claim 1, wherein maintaining the supply voltage above the bias threshold during low power consumption of the load prevents the primary from entering an under-voltage lockout mode in which the master controller is prevented from controlling the output voltage by controlling the primary.

10. The power supply apparatus according to claim 1, further comprising:

a transformer including a primary winding, an auxiliary winding, and a secondary winding;

wherein the primary winding and the auxiliary winding of the transformer are arranged in the primary; and is

Wherein the secondary winding of the transformer is arranged in the secondary.

11. The power supply device of claim 10, wherein the auxiliary winding in the primary is operable to generate the supply voltage having a magnitude that varies with an amount of energy transferred from the primary winding to the secondary winding to generate the output voltage.

12. The power supply apparatus of claim 1, wherein the secondary comprises a feedback circuit operable to communicate a control signal to the primary, the control signal controlling activation of a switching circuit in the primary during a condition in which power consumption of the load is above a threshold level; and is

Wherein activation of the switching circuit by the control signal: i) transferring energy from the primary to the secondary, and ii) increasing the magnitude of the supply voltage to be substantially above the bias threshold.

13. The power supply apparatus of claim 1, wherein the bias controller is operable to maintain the supply voltage above the bias threshold during deactivation of a switching circuit in the primary, the deactivation of the switching circuit in the primary being operable to terminate energy transfer from the primary to the secondary to generate the output voltage.

14. The power supply apparatus of claim 7, wherein the maximum bias threshold is an adaptive threshold based at least in part on a magnitude of the output voltage.

15. A method of generating an output voltage from a voltage converter comprising a primary and a secondary, the method comprising:

receiving a power supply voltage signal;

adjusting a transfer of energy from the primary to the secondary based on a magnitude of a feedback signal, the adjustment of the transfer controlling a magnitude of an output voltage output from the secondary to power a load; and

maintaining the supply voltage above a first bias threshold.

16. The method of claim 15, wherein maintaining the supply voltage comprises:

comparing the supply voltage to the first bias threshold; and

activating a switching circuit in the primary in response to detecting that the magnitude of the supply voltage is equal to or below the first bias threshold, the activation of the switching circuit increasing the magnitude of the supply voltage above the first bias threshold.

17. The method of claim 16, further comprising:

deactivating the switching circuit in the primary after activating the switching circuit for a predetermined amount of time to prevent the supply voltage from increasing above a second bias threshold.

18. The method of claim 17, wherein maintaining the supply voltage between the first bias threshold and the second bias threshold has a negligible effect on increasing the magnitude of the output voltage output from the secondary.

19. The method of claim 16, further comprising:

deactivating a switching circuit in the primary in response to detecting the supply voltage is equal to or above a second bias threshold.

20. Computer-readable storage hardware having instructions stored thereon, which when executed by computer processor hardware, cause the computer processor hardware to:

receiving a power supply voltage signal;

adjusting a transfer of energy from a primary to a secondary of a voltage converter based on a magnitude of a received feedback signal, the adjustment of the transfer controlling a magnitude of an output voltage output from the secondary to power a load; and

maintaining the magnitude of the supply voltage above a bias threshold during a period when the current consumption of the load is below a current consumption threshold.

Technical Field

The present invention relates to the field of power supplies, and in particular to bias control in a voltage converter of a power supply.

Background

As the name suggests, conventional voltage converters convert a received input voltage to a corresponding output voltage to power a load.

Some power supplies include a primary winding, a secondary winding, and an auxiliary winding to generate an output voltage. The voltage signal generated by the primary winding may be used as a basis for generating a supply voltage for powering one or more components. When the controller interrupts the input of energy to the primary winding, the magnitude of the supply voltage produced by the auxiliary winding tends to decrease due to leakage or current draw caused by components in the voltage converter coupled to the auxiliary winding.

Disclosure of Invention

The present disclosure includes the observation that conventional power converters can be improved to provide operation in a wider variety of conditions, such as during deep load dips when the respective load consumes little current. Embodiments herein include novel ways of providing improved performance of a voltage converter and keeping the supply voltage above a threshold even during conditions where the load consumes little or no power.

Specifically, an apparatus (e.g., a power supply) described herein includes a voltage converter, a main controller, and a bias controller. The voltage converter includes a primary and a secondary. The controller is operable to control regulation of the output voltage from the secondary. As the name suggests, the output voltage from the secondary supplies the load. In one embodiment, the voltage converter also generates a supply voltage from a source such as a primary winding. During certain load conditions (e.g., during low power consumption when little or no energy is input to the primary winding to increase the magnitude of the output voltage), the power supply voltage powering the controller tends to decrease, for example, due to a lack of energy input to the primary winding and leakage or current draw caused by components in a voltage converter coupled to the auxiliary winding or other circuitry. A bias controller as described herein is operable (with a novel bias) to maintain the magnitude of the supply voltage above a bias threshold, such that the supply voltage remains above the threshold to power the controller even when no current is input to the primary winding.

In one embodiment, the bias controller is operable to prevent the supply voltage (which may be referred to as the bias voltage, voltage rails, etc.) from falling below a minimum bias threshold, so that the controller can avoid a lock-up mode (e.g., Vcc below the minimum threshold), and since the controller is still powered by a properly regulated supply voltage, quickly transfer sufficient energy from the primary to the secondary as the load increases the rate of consumption of power provided by the output voltage.

Note that any of the components described herein, such as the voltage converter, the main controller, the bias controller, etc., may be instantiated in any suitable manner. For example, in one embodiment, each of the voltage converter, controller, and bias controller is instantiated as digital and/or analog electronic circuitry. It is also noted that any of one or more components of the power supply, such as the voltage converter, the main controller, the bias controller, etc., may be implemented in hardware (e.g., circuitry), software, or a combination of hardware and software.

In one non-limiting exemplary embodiment, the voltage converter includes a transformer including a plurality of windings. The primary includes a primary winding and an auxiliary winding. In such instances, the primary winding is operable to transfer energy received from the input voltage to the secondary winding of the transformer. The auxiliary winding is operable to generate a supply voltage that is biased by the bias controller during the low current consumption mode.

During a first mode in which the load consumes power from the output voltage above a threshold level, the magnitude of the supply voltage is suitably adjusted above the threshold due to the energy input to the primary winding. In contrast, during a second mode in which the load consumes power from the output voltage below the threshold level, the bias controller is operable to apply a bias to the supply voltage to maintain the magnitude of the supply voltage above the (minimum) bias threshold.

Bias control may be implemented in any suitable manner. For example, in one embodiment, the bias controller includes a comparator operable to compare the magnitude of the supply voltage to a minimum bias threshold; and activating a switching circuit in the primary in response to detecting that the magnitude of the supply voltage is substantially equal to (below) the minimum bias threshold, the activation of the switching circuit increasing the magnitude of the supply voltage above the minimum bias threshold, thereby preventing lockout.

In one embodiment, the bias controller deactivates the switching circuit in the primary after biasing the supply voltage derived from the auxiliary winding (or other suitable resource) after activating the switching circuit for a predetermined amount of time. Thus, while energy may not be immediately required to be transferred from the primary winding to the secondary winding to maintain regulation of the output voltage due to low current consumption by the load, the short pulses that activate the switching circuit are sufficient to bias the supply voltage not below the minimum threshold.

Other embodiments herein include maintaining the supply voltage between the minimum bias voltage level and the maximum bias voltage level during the second mode (low power mode). In one embodiment, maintaining the supply voltage between the minimum bias threshold and the maximum bias threshold has negligible or no effect on increasing the magnitude of the output voltage from the secondary.

As previously mentioned, the bias controller may comprise a comparator. In one embodiment, the comparator is operable to compare the supply voltage to a maximum bias threshold. In response to detecting that the magnitude of the supply voltage is substantially equal to or exceeds the maximum bias threshold, the bias controller deactivates the switching circuit in the primary in response to detecting that the magnitude of the supply voltage is substantially equal to the maximum bias threshold.

Further, control of the bias of the supply voltage during light load conditions may be accomplished in any suitable manner. For example, in one embodiment, the bias controller is operable to control the duration of time that the switching circuitry (e.g., one or more switches) in the primary is activated such that the magnitude of the supply voltage is maintained below a maximum bias threshold; activation of the switching circuit may transfer a small portion of the energy from the primary to the secondary. However, a small portion of the energy may or may not cause the magnitude of the output voltage powering the corresponding load to vary.

According to other embodiments, during low power consumption of the load, maintaining the supply voltage above the minimum bias threshold prevents the primary (and the controller powered by the supply voltage signal) from entering an under-voltage lockout mode in which the main controller is prevented or prevented from controlling the output voltage by control of the primary because the main controller is not properly powered.

In other embodiments, the voltage converter may be configured to include a transformer, as previously described. The transformer includes a primary winding, an auxiliary winding, and a secondary winding. The primary winding and the auxiliary winding of the transformer are arranged at the primary side; the secondary winding of the transformer is arranged on the secondary side. The auxiliary winding in the primary is operable to generate a supply voltage. As previously described, in some cases, the magnitude of the supply voltage varies with the amount of energy transferred from the primary winding to the secondary winding to generate the output voltage.

According to other embodiments, the secondary may be configured to include a feedback circuit (or generator) operable to transmit control (feedback) to the primary, the feedback control signal being configured to control activation of the switching circuit in the primary during conditions in which the power consumption of the load is above a threshold level. Feedback from the secondary may be configured to control activation of a switching circuit in the primary to transfer energy from the primary to the secondary. In one embodiment, the secondary can only occasionally provide feedback to activate the switch in the primary to increase the output voltage when the load is in a low power consumption mode, which also increases the magnitude of the supply voltage generated by the primary winding. Thus, during relatively low (load) power consumption conditions, the secondary may cause the magnitude of the supply voltage to increase.

As previously described, the bias controller as described herein operates to bias the supply voltage in extreme conditions where even the secondary does not initiate activation of the switch in the primary. After a low load consumption condition and recovery of a higher amount of current by the load, activation of the switching circuit under normal switching conditions will naturally increase the magnitude of the supply voltage sufficiently above the minimum bias threshold such that the bias controller no longer needs to bias the supply voltage above the minimum bias threshold. Thus, the need to bias the supply voltage by the bias controller may depend on the amount of power or current consumed by the load.

Accordingly, embodiments herein include a bias controller that can maintain a supply voltage above a minimum bias threshold during overall deactivation of a high-side switching circuit and a low-side switching circuit in a primary. As previously described, activation of the switching circuit in the primary transfers energy from the primary to the secondary to produce an output voltage. Deactivation of the switching circuit in the primary is operable to terminate energy transfer from the primary to the secondary to generate the output voltage, in which case the bias controller acts as a watchdog to maintain the magnitude of the supply voltage above or between a minimum threshold and a maximum threshold.

According to other embodiments, the minimum bias threshold is an adaptive threshold that powers the load based at least in part on a magnitude of an output voltage output from the secondary.

Embodiments herein are useful over conventional techniques. For example, the bias controller and associated topology provide for sustained use of the voltage converter during high power consumption fluctuations of the load as compared to conventional techniques. That is, biasing the supply voltage in the manner described herein prevents the supply voltage (such as generated from the auxiliary winding) and the corresponding primary from entering an under-voltage lockout mode, in which the controller is prevented from controlling the output voltage.

These and other more specific embodiments are disclosed in more detail below.

Note that any resources discussed herein may include one or more computerized devices, apparatus, hardware, etc. that perform and/or support the operations of any or all of the methods disclosed herein. In other words, one or more computerized devices or processors can be programmed and/or configured to operate as explained herein to perform the different embodiments described herein.

Other embodiments herein include software programs for performing the steps and/or operations outlined above and disclosed in detail below. One such embodiment includes a computer program product that includes a non-transitory computer-readable storage medium (i.e., any computer-readable hardware storage medium) on which software instructions are encoded for subsequent execution. When executed in a computerized device (hardware) having a processor, the instructions program and/or cause the processor (hardware) to perform the operations disclosed herein. Such arrangements are typically provided as software, code, instructions and/or other data (e.g., data structures) arranged or encoded on a non-transitory computer readable storage medium, such as an optical medium (e.g., CD-ROM), floppy disk, hard disk, memory stick, storage device, etc., or other medium such as firmware in one or more ROMs, RAMs, PROMs, etc., or as an Application Specific Integrated Circuit (ASIC), etc. The software or firmware or other such configurations can be installed onto a computerized device to cause the computerized device to perform the techniques described herein.

Accordingly, embodiments herein are directed to methods, systems, computer program products, and the like, that support the operations discussed herein.

One embodiment includes a computer-readable storage medium and/or system having instructions stored thereon to facilitate signal biasing and corresponding control of a voltage converter to generate an output voltage to power a load. The instructions, when executed by computer processor hardware, cause the computer processor hardware (e.g., one or more identically or differently located processor devices or hardware) to: receiving a feedback signal; adjusting the transfer of energy from the primary to the secondary based on the magnitude of the received feedback signal, the adjustment of the transfer controlling the magnitude of the output voltage output from the secondary to power the load; and maintaining the supply voltage (e.g., from the primary) above the bias threshold during deactivation of the switching circuit, which terminates energy transfer from the primary to generate the output voltage.

Another embodiment includes a computer-readable storage medium and/or system having instructions stored thereon that facilitate generating an output voltage to power a load. The instructions, when executed by computer processor hardware, cause the computer processor hardware (e.g., one or more identically or differently located processor devices or hardware) to: comparing the received supply voltage to a bias threshold; in response to detecting that the magnitude of the supply voltage crosses (is substantially equal to) the bias threshold, activating a switching circuit in a primary of the voltage converter, the activation of the switching circuit increasing the magnitude of the supply voltage above the bias threshold; and i) activating the switching circuit for a predetermined amount of time, or ii) deactivating the switching circuit in the primary of the voltage converter in response to detecting that the supply voltage exceeds (increases above) a magnitude of a second threshold (a maximum bias threshold) to prevent the supply voltage from increasing above the second threshold.

The order of the above steps has been increased for clarity. Note that any of the process steps discussed herein can be performed in any suitable order.

Other embodiments of the present disclosure include software programs and/or corresponding hardware to perform any of the method embodiment steps and operations summarized above and disclosed in detail below.

It should be understood that the systems, methods, devices, instructions on a computer-readable storage medium, etc. discussed herein may also be implemented strictly as a software program, firmware, as a mixture of software, hardware, and/or firmware, or simply as hardware, such as within a processor (either hardware or software), or within an operating system or software application.

It is also noted that although the embodiments discussed herein are applicable to controlling the operation of a voltage converter, the concepts disclosed herein may be advantageously applied to any other suitable voltage converter topology.

Additionally, it is noted that although each of the different features, techniques, configurations, etc. herein may be discussed in different places of this disclosure, each concept may alternatively be performed independently of each other or in combination with each other, where appropriate. Thus, one or more of the inventions described herein may be embodied and viewed in many different ways.

Additionally, it is noted that the preliminary discussion of embodiments herein (a brief description of embodiments) is not intended to specify each embodiment and/or incrementally novel aspect of the disclosure or claimed invention. In contrast, this brief description presents only the general embodiments and the corresponding points of novelty, compared to the conventional art. As discussed further below, the reader is directed to the detailed description section of the disclosure (which is a summary of the embodiments) and the corresponding figures of the disclosure for further details and/or possible perspectives (permutations) of the invention.

Drawings

Fig. 1 is an example diagram illustrating a power supply including a main controller and a bias controller according to embodiments herein;

FIG. 2 is an example diagram illustrating a power supply according to embodiments herein;

fig. 3 is an example diagram illustrating a timing diagram for operating a voltage converter in multiple modes according to embodiments herein;

fig. 4 is an example diagram illustrating a timing diagram for operating a voltage converter in multiple modes according to embodiments herein;

FIG. 5 is an example diagram illustrating a computer architecture operable to perform one or more operations according to embodiments herein;

fig. 6 is an exemplary diagram illustrating a general method according to embodiments herein.

The foregoing and other objects, features and advantages of embodiments herein will be apparent from the following more particular descriptions, as illustrated in the accompanying drawings wherein like reference numbers refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the embodiments, principles, concepts, and so forth.

Detailed Description

A power supply as described herein includes a voltage converter, a main controller, and a bias controller. The voltage converter includes a primary and a secondary. During operation, the controller is operable to control regulation of the output voltage from the secondary based on a supply voltage generated in the primary. The output voltage from the secondary supplies the load. During certain load conditions, such as low current consumption, the bias controller maintains the magnitude of the supply voltage (through the novel bias) above a (minimum) bias threshold or between the minimum and maximum bias thresholds. In one embodiment, the bias controller is operable to prevent the supply voltage from falling below a minimum bias threshold (i.e., voltage value), preventing an under-voltage lockout condition of the supply voltage, such that the transfer controller can quickly continue the transfer of sufficient energy from the primary to the secondary as the load increases the rate of consumption of power provided by the output voltage. In addition, during low current consumption of the load, the bias controller prevents the supply voltage from increasing above a maximum bias threshold, thereby preventing the magnitude of the output voltage from increasing.

Now, specifically, fig. 1 is an example diagram illustrating a power supply according to embodiments herein.

As shown in this example embodiment, power supply 100 (e.g., an appliance, an electronic device, etc.) includes a main controller 140 and a voltage converter 135. The voltage converter 135 generates an output voltage 123 that powers the load 118.

Main controller 140 includes a bias controller 141. Alternatively, bias controller 141 is positioned differently with respect to main controller 140.

By way of another non-limiting example embodiment, the voltage converter 135 includes a primary 101 and a secondary 102. The voltage converter 135 also includes a corresponding transformer 160.

The transformer 160 includes a primary winding 161, a secondary winding 162, and an auxiliary winding 163. The combination of the primary winding 161, the secondary winding 162, and the auxiliary winding 163 are magnetically coupled to each other.

In this example embodiment, the primary 101 includes one or more switches 125, the one or more switches 125 controlling the operation of transferring energy received from the input voltage 120 through the primary winding 161 to the secondary winding 162 of the transformer 160.

In one embodiment, the regulation of the transfer of energy received from input voltage 120 from primary winding 161 to the secondary winding of secondary 102 results in the generation of an output voltage 123 that powers load 118. The regulation of the transfer of energy from primary winding 161 to secondary winding 162 maintains the magnitude of output voltage 123 within a desired range for powering load 118.

Note that each of the resources, components, modules, etc. described herein can be instantiated in any suitable manner. For example, each of main controller 140, bias controller 141, voltage converter 135, etc. may be instantiated or include hardware (e.g., electronic circuitry), software (e.g., a set of instructions executed), or a combination of hardware and software resources.

Additionally, note that the hardware implementation and corresponding components, resources, etc. associated with power supply 100 may be instantiated as a combination of digital circuitry, analog circuitry, or both analog/digital electronic circuitry.

In general, the feedback signal 252 received from the voltage converter 135 indicates the magnitude of the output voltage 123 and/or whether more energy is needed at the secondary winding 162 to maintain the output voltage 123 within a proper regulation range. During normal load conditions that transfer sufficient energy above the threshold from the primary winding 161 to the secondary winding, the auxiliary winding 163 receives sufficient energy to maintain the magnitude of the supply voltage 175 (which may be referred to as a bias voltage, voltage rail, etc.) above the threshold to power the controller 140.

During certain load conditions, such as those below a threshold (e.g., conditions in which the load 118 consumes only a low level of current from the output voltage 123), the magnitude of the supply voltage 175 tends to decrease to a low magnitude that causes the master controller 140 (as indicated by feedback 252) to no longer need to activate one or more switches 125 to transfer energy from the primary 101 to the secondary 102 to increase the magnitude of the output voltage 123.

In one embodiment, when switch 125 is deactivated, main controller 140 no longer transfers energy from the primary winding to the secondary winding to increase the magnitude of the output voltage, the magnitude of supply voltage 175 may drop at a faster rate than output voltage 123, e.g., due to parasitic consumption of components and/or circuitry in voltage converter 135 and/or controller 140 itself, which consumes power provided by supply voltage 175.

In some instances, as previously described, it is undesirable for the magnitude of the supply voltage 175 to fall below the threshold Vth 1. As described herein, the bias controller 141 prevents such a condition.

For example, according to other embodiments, the bias controller 141 acts as a monitor or watchdog circuit that prevents the magnitude of the supply voltage 175 from falling below a threshold value during low load conditions. That is, by generating the control signal 105 through the novel biasing as discussed further herein, the bias controller 141 maintains the magnitude of the supply voltage 175 (e.g., derived from the output of the auxiliary winding 163) above the bias threshold Vth 1.

According to other embodiments, the bias controller 141 is operable to prevent the supply voltage 175 from falling below the minimum bias threshold Vth1, such that when the load 118 suddenly increases the rate of power consumption provided by the output voltage 123 (e.g., in response to a transient current consumption condition), the main controller 140 (since the controller 140 is powered by the healthy supply voltage 175 when biased) can quickly transfer sufficient energy (received from the input voltage 120) from the primary 101 (i.e., the primary side of the voltage converter 135) to the secondary 102 (i.e., the secondary side of the voltage converter 135). Bias controller 141 also prevents supply voltage 175 from increasing above the maximum bias threshold, thereby preventing an increase in the magnitude of output voltage 123 and possible offset conditions in which the magnitude of output voltage 123 may exceed the maximum allowable output value (which may damage load 118).

Specific details of these embodiments are discussed further below.

Fig. 2 is an example diagram illustrating a power supply according to embodiments herein.

As shown in a more detailed embodiment, power supply 100 includes a main controller 140 and a voltage converter 135.

Main controller 140 includes bias controller 141 as well as driver 221 and driver 222. In this example embodiment, the bias controller 141 includes a comparator 241.

As previously described, the voltage converter 135 includes the primary 101 and the secondary 102. Driver 221 of main controller 140 is coupled to drive and control the gate of switch 125-1 via control signal 105-1. Driver 222 of main controller 140 is operable to drive and control the gate of switch 125-2 with control signal 105-2.

In this example embodiment, primary 101 includes feedback circuit 201, monitor circuit 275, switch 125-1, switch 125-2, inductor L1, inductor L2, capacitor C1, primary winding 161, and auxiliary winding 163. Inductors L1 and L2 and capacitor C1 support the resonant operation of power supply 101. When the LLC circuit is not switching, both the high side switch 125-1 and the low side switch 125-2 are off.

As further shown, the drain node of switch 125-1 is connected to input voltage 120. The source node of switch 125-1 is connected to the drain of switch 125-2. The source node of switch 125-2 is connected to a ground reference voltage.

As further shown, inductor L1 is coupled between the source node of switch 125-1 and primary winding 161. Inductor L2 is connected in parallel across primary winding 161. Capacitor C1 provides connectivity between the combination of inductor L2 and primary winding 161 and the source node of switch 125-2, which is connected to a ground reference.

The monitor circuit 275 of the primary 101 includes a diode D1, a diode D2, an auxiliary winding 163, and a capacitor Cvcc. As shown, diode D1 of monitor circuit 275 is coupled between a first node or terminal of auxiliary winding 163 and node 238. Diode D2 of monitor circuit 275 is coupled between a second node or terminal of auxiliary winding 163 and node 238. Capacitor Cvcc is connected between node 238 and ground. Node 238 is coupled to input node Vcc of main controller 140.

The feedback circuit 202 receives the output voltage 123 and generates a feedback signal 251 that is transmitted to the optocoupler 291. Feedback circuit 201 couples optocoupler 291 to the HBFB node of main controller 140. In one embodiment, optocoupler 291 generates a feedback signal 252 (from feedback signal 251), which feedback signal 252 is fed through feedback circuit 201 to the HBFB node of master controller 140.

The secondary 102 also includes a switch 225-1 driven by the control signal SR0, a switch 225-2 driven by the control signal SR1, a diode D3, a diode D4, a capacitor Cout, and a feedback circuit 202.

As shown, diode D3 is coupled in parallel between the drain node of switch 225-1 and the source node of switch node 225-1. The drain node of switch 225-1 is connected to a first end of secondary winding 162. The source node of switch 225-1 is connected to a second ground reference.

Diode D4 is coupled in parallel between the drain node of switch 225-2 and the source node of switch node 225-2. The drain node of switch 225-2 is connected to the second end of secondary winding 162. The source node of switch 225-2 is connected to a second ground reference.

The (center) tap node of secondary winding 162 is coupled to node 277. Capacitor Cout is coupled between node 277 and a second ground reference voltage. The capacitor Cout stores the output voltage 123.

Feedback circuit 202 is coupled to node 277 to monitor output voltage 123. As described above, the feedback circuit 202 generates the signal 251 that is input to the optocoupler 291. The optocoupler 291 converts the received signal 251 into a corresponding output feedback signal 252 that is communicated to the HBFB node of the master controller 140.

In addition, as shown diagrammatically in fig. 2, a transformer 160 provides a coupling that supports the transfer of energy from the primary 101 to the secondary 102. As previously discussed, in the opposite direction, the optocoupler 291 provides a way to communicate the feedback 252 from the feedback circuit 202 to the feedback circuit 201 and the corresponding HBFB node of the master controller 140. In one embodiment, feedback signal 252 is indicative of the magnitude of output voltage 123; the controller 140 uses the feedback signal 252 as a basis to control the switch 125 and maintain the magnitude of the output voltage 123 within a desired voltage range.

The power supply 100 includes a bias controller 141. Note that bias control may be implemented in any suitable manner (by bias controller 141 or other suitable resource).

In one embodiment, bias controller 141 includes one or more comparators, such as comparator 241.

The comparator 241 is operable to: the magnitude of the supply voltage 175 is compared to a threshold Vth1 (e.g., a minimum offset threshold). Through one or more bias control signals 268 output from the bias controller 141, the bias controller 141 activates the switching circuit 125 in the primary 101 in response to detecting that the magnitude of the supply voltage 175 is substantially equal to or less than the minimum bias threshold Vth 1.

For example, activation (switching) of the switch circuit (e.g., switch 125-1 and switch 125-2 are switched between on and off, such as switch 125-1 being on and switch 125-2 being off in a first cycle, switch 125-1 being off and switch 125-2 being on in a second cycle, switch 125-1 being on and switch 125-2 being off in a third cycle, switch 125-1 being on and switch 125-2 being off in a fourth cycle, switch 125-1 being off and switch 125-2 being on in a fourth cycle, and so on during activation) causes current to flow from input voltage 120 through primary winding 161 by generating control signal 105; the auxiliary winding 163 receives a portion of the energy, increasing the magnitude of the voltage 175 above the minimum bias threshold Vth 1. Note that deactivation of the switch circuit 125 means that both the switch 125-1 and the switch 125-2 are set to the off state. Note also that both switch 125-1 and switch 125-2 are never on at the same time, as this would short source 120(Vin) to the respective ground references.

In one embodiment, the bias controller 141 deactivates (opens both switches 125-1 and 125-2) the switching circuit 125 in the primary 101 after activation (switching as previously discussed) of the switching circuit 125 for at least a short duration to bias the supply voltage 175 derived from the auxiliary winding 163 (or other suitable resource). Thus, while it may not be immediately necessary to transfer energy from the primary winding 161 to the secondary winding 162 to keep the output voltage 123 stable (e.g., increase its magnitude), the short pulses that activate the switching circuit 125 are sufficient to bias the voltage 175 such that the voltage 175 does not substantially fall below the minimum threshold Vth 1. In one embodiment, supply voltage 175 requires only loose regulation (must be above UVLO and below absolute maximum rating). The embodiments herein include controlling the winding or turns ratio of the transformer 160 to keep Naux Vbias always below Ns Vout, where Ns is the number of turns on the secondary winding 162 and Naux is the number of turns on the auxiliary winding 163; vbias Vcc or supply voltage 175.

Note that as an alternative to activating the switching circuit 125 for a predetermined amount of time, other embodiments herein include during the second mode of biasing the supply voltage 175(Vcc) during low current consumption of the load 118, the bias controller 141 may be configured to maintain the supply voltage 175 between a minimum voltage level (e.g., Vth1) and a maximum bias voltage level (Vth2), as discussed further below.

In one embodiment, maintaining the supply voltage 175 above the threshold Vth1 or between the minimum and maximum offset thresholds Vth1 and Vth2 has negligible or no effect on increasing the magnitude of the output voltage 123 from the secondary 102.

Embodiments herein are useful over conventional techniques. For example, in contrast to conventional techniques, the bias controller and related topology provide for sustained use of the voltage converter during large power consumption fluctuations of the load. That is, biasing the voltage in the manner described herein may prevent the supply voltage 175 (such as the voltage from the auxiliary winding) and the corresponding primary from entering an under-voltage or locked-out mode in which the controller is prevented from controlling the output voltage.

Where Np is the number of turns of primary winding 161; ns — the number of turns of the secondary primary winding 162; naux is the number of turns of the auxiliary winding 163.

During switching by feedback regulation, Vout (output voltage 123) and Vcc (supply voltage 175) are defined by the turns ratio of the transformer 160 (see equations 1 and 2).

But during the burst phase, Vout and Vcc are reduced according to their load

Then, VCC may fall below its minimum "survival" or lockout level:

after Vcc drops, switching by the bias controller 141 returns it to a level well above the minimum "survivor" (Vcc.

At the same time, the activation of the switching circuit 125 will charge the output capacitor Cout only if the associated "new" output voltage (vnew. out) is higher than the present magnitude of the output voltage 123.

As long as the "new" Vout (also called vnew. out) is lower than the actual magnitude of the output voltage 123, only the voltage 175 of the capacitor Cvcc will be charged (the voltage magnitude increases). Thus, the number of turns associated with each winding may be used to facilitate biasing of voltage 175.

For example: NAUX/NS is 1.33, VOUT is 12VV, "VCC" is 16V, and now if VCC is 15V, vnew, out is 15V/1.33 is 11.27V <12V, the output voltage 123 does not increase.

In the exemplary embodiment, controller 140 provides for the generation of Vcc (supply voltage 175) without significant side effects (e.g., it is not necessary to increase the magnitude of output voltage 123 when load 118 does not draw enough current to warrant further charging of capacitor Cout).

Fig. 3 is an example diagram illustrating a timing diagram for operating a voltage converter in multiple modes according to embodiments herein.

Graph 300 illustrates controlling energy transfer from primary winding 161 to secondary winding 162 to maintain output voltage 123 in a first mode and a bias to voltage 175(Vcc) during a second mode according to embodiments herein.

During a first mode (e.g., between time T1 and time T5) in which load 118 consumes power from output voltage 123 (e.g., above a threshold consumption level), the magnitude of voltage 175 can operate to proportionally track the magnitude of output voltage 123 as a function of the number of turns in the winding of transformer 160.

As previously discussed, the controller 140 receives feedback 252 from the secondary 102. Specifically, in this example embodiment, the controller 140 receives feedback 252 at the HBFB node of the controller 140.

In response to detecting an increase in the magnitude of the signal HBFB to HBFB at time T1_{LLC SW-ON}The controller 140 initiates the activation of the switching circuit 125 to the on state by a pulse (one or more times) of the control signals 105-1 and 105-2 between or near times T1 and T2. As previously described, during activation of the switch circuit 125, the switch 125-1 is turned on and the switch 125-2 is turned off by the control signals 105-1 and 105-2; when the control switch 125-2 is controlled to be on, the switch 125-1 is controlled to be off (see the above activation example). Note that control signal 105-1 and control signal 105-2 between times T1 and T2 may include one or more pulses (e.g., a high side burst and a low side burst), depending on the implementation.

As further shown, activating switches 125-1 and 125-2 at different times between times T1 and T2 in the manner previously discussed causes the magnitude of output voltage 123 to increase and the magnitude of voltage 175(Vcc) to increase.

In a similar manner, during the first mode, between times T3 and T4, based on the received feedback signal 252, the controller 140 initiates activation of the control switch circuit 125 to a conductive state by pulses of the control signals 105-1 and 105-2 between times T3 and T4.

In contrast, during a second mode (e.g., between times T5 and T9) in which load 118 consumes very little power (or current) provided from output voltage 123 (e.g., below a threshold level), bias controller 141 is operable to apply a bias to supply voltage 175 to maintain the magnitude of voltage 175 above minimum bias threshold Vth 1.

More specifically, during the second mode after time T5, the master controller 140 receives feedback 252. However, in this example embodiment, the feedback 252 does not cause the master toThe controller 140 applies a pulse to the switching circuit 125; thus, between times T6 and T9, the magnitude of feedback 252 does not rise above the threshold HBFB_{LLC SW-ON}. However, as previously described, the bias controller 141 compares the voltage 175 to the voltage threshold Vth 1. In response to detecting that the magnitude of the voltage 175 (at node Vcc) crosses (is substantially equal to or is about to be below) the minimum threshold Vth1, the bias controller 141 initiates activation of the switching circuit 125 to the on state at time T6 or around time T6 via pulses of the control signals 105-1 and 105-2.

In one embodiment, the bias controller 141 also compares the supply voltage 175 to a voltage threshold Vth2 (e.g., a maximum threshold). In response to detecting an increase in the magnitude of the supply voltage 175 (at node Vcc of the main controller 140) to, for example, exceed the maximum threshold Vth2, the bias controller 141 initiates activation of the control switch circuit to an OFF state by terminating the pulses of the control signals 105-1 and 105-2 around time T7. Accordingly, the bias controller 141 initiates a burst of activation switch circuits 125 between times T6 and T7 to maintain the power supply 175 above a minimum threshold.

As mentioned, according to an embodiment, the control signals 105-1 and 105-2 between the activation times T6 and T7 may include one or more pulses (e.g., high side burst pulses).

As further shown, activating the switch circuit 125 between times T6 and T7 causes the supply voltage 175 (e.g., Vcc) to increase in magnitude; however, the magnitude of the supply voltage 175(Vcc) does not change because the voltage on the secondary winding is less than the current magnitude of the output voltage 123.

In a typical BM (burst mode) fixed fluctuation controller, the HBFB node can set the LLC turn-off threshold. When Vcc (supply voltage 175) falls below V_CC.LLCONAt threshold (Vth1), controller 141 activates the LLC switch with respect to primary winding 161 to avoid when supply voltage 175 drops below a lockout voltage V_CC.UV-LOA locked mode that occurs. Thereafter, since the magnitude of the power supply voltage 175(Vcc) is increased to be higher than V_CC.LLCOFFA threshold value (Vth2) and thus the bias controller 141 interrupts the LLC (resonance) with respect to the primary winding 161. In a fruitIn an embodiment, the controller provides Vcc regulation without adverse effects on the output voltage 123 as long as the associated vout. Note that V_CC.LLCONAnd V_CC.LLCOFFThe thresholds may be the same or different threshold settings.

Fig. 4 is an example diagram illustrating a timing diagram for operating a voltage converter in multiple modes according to embodiments herein.

Graph 400 illustrates controlling energy transfer from primary winding 161 to secondary winding 162 during a first mode to maintain output voltage 123 and biasing of supply voltage 175(Vcc) during a second mode according to embodiments herein.

During a first mode (e.g., between time T11 and time T15) in which load 118 consumes power from output voltage 123 above a threshold level, as shown, the magnitude of supply voltage 175 is operable to proportionally track the magnitude of output voltage 123 as a function of the number of turns in the winding of transformer 160.

In a manner similar to that previously discussed, the controller 140 receives feedback 252 from the secondary 102. Specifically, main controller 140 and bias controller 141 receive feedback 252 at the HBFB node of controller 140.

In response to detecting an increase in the magnitude of the feedback 252 signal at the node HBFB to HBFB_{LLC SW-ON}The controller 140 initiates activation of the switching circuit 125 to the on state by pulses of the control signals 105-1 and 105-2 between times T11 and T12. Note that, according to an embodiment, control signals 105-1 and 105-2 between times T11 and T12 may include one or more pulses (e.g., a high side burst and a low side burst).

As shown, activation of the switch circuit 125 between times T11 and T12 causes the magnitude of the output voltage 123 to increase, and the magnitude of the voltage 175(Vcc) to increase.

In a similar manner, during the first mode, between times T13 and T14, the controller 140 initiates activation of the switching circuit 125 to the conductive state by pulses of the control signals 105-1 and 105-2 between times T13 and T14 based on the feedback signal 252.

In contrast, during a second mode (e.g., between times T15 and T18) in which load 118 consumes very little power (or current) provided from output voltage 123 (e.g., below a consumption threshold level), bias controller 141 may be operable to apply a bias to supply voltage 175 to maintain the magnitude of supply voltage 175 above a minimum bias threshold Vth1 (V) of voltage_CC.LLC-ON) Minimum offset threshold Vth1 (V)_CC.LLC-ON) Above undervoltage lockout threshold V_CC.UV-LO. (this will prevent further operation of the voltage converter 135 due to the power supply entering the locked mode).

More specifically, during the second mode, the controller 140 receives feedback 252 from the second stage 102 through the feedback circuit 202 and the feedback circuit 201. However, in this exemplary embodiment, between times T15 and T17, feedback 252 does not cause main controller 140 to apply the high-side and low-side bursts to switching circuit 125 because feedback 252 does not rise above threshold HBFB between times T15 and T17_{LLC SW-ON}. However, during such a period of time after time T15, the bias controller 141 compares the magnitude of the supply voltage 175 to the voltage threshold Vth1 (V)_CC.LLC-ON) A comparison is made.

In response to detecting that the magnitude of the supply voltage 175 (at node Vcc) crosses (is substantially equal to or is about to fall below) the minimum threshold Vth1 (V)_CC.LLC-ON) Bias controller 141 initiates activation of switching circuit 125 to the on state by controlling the pulses of signals 105-1 and 105-2 in the vicinity of time T16. In this exemplary embodiment, instead of comparing the supply voltage 175 to a second voltage threshold Vth2 (e.g., a maximum threshold) to terminate the pulse of the switching circuit 125, the bias controller 141 maintains the activation of the switching circuit 125 for a predetermined amount of time relative to the switch activation time T16.

In response to detecting the expiration of the predetermined amount of time at time T17, the bias controller 141 terminates the activation of the control switch circuit 125 to the OFF state by terminating the pulses of the control signals 105-1 and 105-2 near time T17. Accordingly, the bias controller 141 initiates a burst of activation switch circuit 125 between times T16 and T17 to bias the supply voltage 175 (Vcc).

Note that, according to an embodiment, the control signals 105-1 and 105-2 between times T16 and T17 may include one or more pulses (e.g., a high side burst and a low side burst).

As further shown in graph 400, activating the switch circuit 125 between times T16 and T17 causes the magnitude of the supply voltage 175 to increase; however, since the voltage at the secondary winding 162 is less than the present magnitude of the output voltage 123, there is no change in the magnitude of the output voltage 123.

Thus, in a typical BM (burst mode) fixed fluctuation controller, the HBFB node of the main controller 140 may set the LLC turn-off threshold. When Vcc is reduced to V_CC.LLCONBelow the threshold, the controller 141 activates the LLC switch (pulse burst) for a predetermined amount of time (or a minimum amount of time). Thereafter, after termination, since the magnitude of the voltage 175(Vcc) is increased to be higher than V_CC.LLCOFFThe threshold value, and thus the resonant operation of the LLC circuit, is stopped. In one embodiment, the controller provides Vcc modulation (of supply voltage 175) as long as the associated vout. new is below the magnitude of output voltage 123, with no adverse effect on output voltage 123. Note that V_CC.LLCONAnd V_CC.LLCOFFThe thresholds may be the same or different threshold settings.

As previously mentioned, embodiments herein are useful over conventional techniques. For example, controlling the voltage converter 135 to provide a combination of regulation of the output voltage 123 (during the first mode of normal range current consumption) and controlling the bias of the supply voltage 175 above the threshold Vth1 (during the second mode of very low current consumption of the load 118) ensures that the voltage converter 135 avoids a lockout condition during the low current consumption mode. The bias of the supply voltage 175 is controlled below the threshold Vth2 (during the second mode of very low current consumption of the load 118) to ensure that the output voltage 123 does not increase unnecessarily during the low current consumption mode. The low power consumption of the bias supply voltage 175 provides more efficient power conversion using simple circuitry.

FIG. 5 is an example block diagram of a computer system for implementing any of the operations previously discussed in accordance with embodiments herein.

Any of the resources (e.g., main controller 140, bias controller 141, voltage converter 135, etc.) as discussed herein may be configured to include computer processor hardware and/or corresponding executable instructions to perform the different operations as discussed herein.

As shown, the computer system 550 of the present example includes an interconnect 511, the interconnect 511 being operable to couple a computer-readable storage medium 512, such as a non-transitory type of medium (which may be any suitable type of hardware storage medium in which digital information may be stored and retrieved), a processor 513 (computer processor hardware), I/O interfaces 514, and a communications interface 517.

The I/O interface 514 supports connections to a storage 580.

The computer-readable storage medium 512 may be any hardware storage device such as a memory, an optical storage device, a hard drive, a floppy disk, and so forth. In one implementation, computer-readable storage medium 512 stores instructions and/or data.

As shown, the computer-readable storage medium 512 may be encoded with a controller application 140-1 (e.g., comprising instructions) to perform any of the operations discussed herein.

During operation of one embodiment, the processor 513 accesses the computer-readable storage medium 512 using the interconnect 511 to launch, run, execute, interpret or otherwise execute instructions in the controller application 140-1 stored on the computer-readable storage medium 512. Execution of the controller application 140-1 results in a controller process 140-2 to perform any of the operations and/or processes discussed herein.

Those skilled in the art will appreciate that the computer system 550 may include other processes and/or software and hardware components, such as an operating system that controls the allocation and use of hardware resources to execute the controller application 140-1.

According to various embodiments, it is noted that the computer system may be located in any of a variety of types of devices, including but not limited to a power supply, a switched capacitor converter, a power converter, a mobile computer, a personal computer system, a wireless device, a wireless access point, a base station, a telephone device, a desktop computer, a laptop computer, a notebook, a netbook computer, a host system, a handheld computer, a workstation, a network computer, an application server, a storage device, a consumer electronic device such as a camera, a camcorder, a set-top box, a mobile device, a video game console, a handheld video game device, a peripheral device such as a switch, a modem, a router, a set-top box, a content management device, a handheld remote control device, any type of computing or electronic device, and the like. The computer system 550 may be located anywhere, or may be included in any suitable resource in any network environment, to implement the functionality discussed herein.

The functionality supported by the different resources will now be discussed by means of the flow chart in fig. 6. Note that the steps in the following flow charts may be performed in any suitable order.

Fig. 6 is a flow chart 600 illustrating an exemplary method according to embodiments herein. Note that there is some overlap in the concepts discussed above.

In process operation 610, main controller 140 receives the supply voltage 175 of primary 101 from voltage converter 135.

In process operation 620, the master controller 140 regulates the transfer of energy from the primary 101 (such as primary winding 161) to the secondary 102 (such as secondary winding 162) based on the magnitude of the feedback voltage signal 252. The regulation of the energy transfer controls, at least in part, the magnitude of the output voltage 123 output by the secondary 102 to power the load 118.

In process operation 630, the bias controller 141 maintains the supply voltage 175 above a bias threshold (e.g., threshold Vth1) during a low current consumption mode of the load 118, e.g., when the switch 125 in the primary 101 of the voltage converter 135 is deactivated, which terminates or substantially reduces the transfer of energy from the primary 101 to the secondary 102 to generate the output voltage 123. Since energy does not need to be transferred from primary winding 161 to secondary winding 162 during the low current consumption mode, the magnitude of supply voltage 175 is monitored and prevented from falling below a threshold value, as discussed further below.

In sub-processing operation 632 associated with processing operation 630, to maintain the supply voltage 175 above the minimum threshold Vth1, the bias controller 141 compares the magnitude of the supply voltage 175 to the bias threshold Vth 1.

In a sub-processing operation 634 associated with processing operation 630, the bias controller 141 activates the switching circuit 125 in the primary 101 in response to detecting that the magnitude of the supply voltage 175 crosses or is substantially equal to the bias threshold Vth 1; activation of the switching circuit 125 increases the magnitude of the supply voltage 175 above the bias threshold Vth 1.

In a sub-processing operation 634 associated with processing operation 630, after activation of the switching circuit 125 for a predetermined amount of time, or detection of the magnitude of the supply voltage 175 exceeding the second threshold (the maximum bias threshold Vth2), the bias controller 141 deactivates the switching circuit 125 in the primary 101 to prevent the supply voltage 175 from increasing above the second threshold Vth 2. As previously described, in one embodiment, the activation of the switching circuit 125 when in the bias mode is sufficiently short in duration that the activation of the switching circuit 125 has negligible or no effect on increasing the magnitude of the output voltage 123.

Note again that the techniques herein are well suited for use in power supply applications. It should be noted, however, that the embodiments herein are not limited to use in such applications, and the techniques discussed herein are well suited for other applications as well (e.g., flyback, forward, half-bridge LLC, and full-bridge power supply architectures, etc.).

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application as defined by the appended claims. These variations are intended to be covered by the scope of the present application. Accordingly, the foregoing description of the embodiments of the present application is not intended to be limiting. Rather, any limitations to the invention are presented in the following claims.