阅读说明：本技术 一种超低输入电压dc/dc升压装置 (Ultra-low input voltage DC/DC booster ) 是由 李博 于 2021-09-18 设计创作，主要内容包括：一种超低输入电压DC/DC升压装置,包括第一晶体管Q1、第二晶体管Q2、电感L1、内部供电模块、PWM产生模块和低压启动控制模块。当电源电压V3未达到相应的电压阈值时,低压启动控制模块根据接收到的反向POK信号,输出一个抬升且周期性的电压信号CLKN驱动所述第二晶体管Q2导通与关闭,使电源电压V3的上升,直到接收到电源OK子模块检测到电源电压V3达到所述预定阈值,则关闭低压启动控制模块。因此,本发明可有效解决升压装置对输入电源电压V1要求的限制,即输入电源电压V1在超低电压情况下,亦可保证DC/DC升压装置正常启动并正常工作。(An ultra-low input voltage DC/DC boosting device comprises a first transistor Q1, a second transistor Q2, an inductor L1, an internal power supply module, a PWM generation module and a low-voltage starting control module. When the power voltage V3 does not reach the corresponding voltage threshold, the low-voltage start-up control module outputs a raised and periodic voltage signal CLKN to drive the second transistor Q2 to turn on and off according to the received reverse POK signal, so that the power voltage V3 rises until the power OK submodule detects that the power voltage V3 reaches the predetermined threshold, and then the low-voltage start-up control module is turned off. Therefore, the invention can effectively solve the limitation of the boosting device on the requirement of the input power supply voltage V1, namely the input power supply voltage V1 can ensure the normal starting and normal work of the DC/DC boosting device under the condition of ultralow voltage.)

1. An ultra-low input voltage DC/DC booster device is used for boosting an input direct-current power supply voltage V1 into a direct-current power supply voltage V2; it is characterized by comprising:

a first transistor Q1, a second transistor Q2, and an inductor L1; the inductor L1 is connected between the DC supply voltage V1 input and the first transistor Q1 and second transistor Q2 drain connection point SW; the source electrode of the first transistor Q1 is grounded, and the source electrode of the second transistor Q2 is connected with the output end of the direct current supply voltage V2;

the internal power supply module is used for generating a power supply voltage V3 for supplying power to each module in the DC/DC booster device according to the power supply voltage V1 and the power supply voltage V2 and judging a power supply threshold of the power supply voltage V3; the power supply OK submodule is used for judging whether the power supply voltage V3 is greater than or equal to a preset threshold value, if so, outputting a forward POK signal, otherwise, outputting a reverse POK signal;

the PWM generating module generates a PWM square wave signal;

the boost system driving control module is used for controlling the grids of the first transistor Q1 and the second transistor Q2 according to the CLKP and the CLKN corresponding to the PWM square wave signal output signal if the received POK signal is positive POK according to the received PWM square wave signal and the POK signal; when the CLKN controls the second transistor Q2 to be turned on and the CLKP controls the first transistor to be turned off, a loop is formed between the power voltage V1 and the ground terminal GND, and at this time, the inductor L1 is charged to store energy; when the CLKN controls the second transistor Q2 to be turned off and the first transistor Q1 to be turned on, a loop is formed between the power voltages V1 and V2, and at this time, a current exists in the inductor L1, because the current in the inductor L1 cannot suddenly change the voltage difference VL formed at the two ends of the inductor L1, and the input power voltage V1 transmits energy to the output power voltage V2 at the same time, so that the voltage of V2 is raised;

and the low-voltage starting control module outputs a lifting and periodic voltage signal CLKN to drive the second transistor Q2 to be switched on and off according to the received reverse POK signal when the power supply voltage V3 does not reach the corresponding voltage threshold value, so that the power supply voltage V3 rises until the power supply OK submodule detects that the power supply voltage V3 reaches the preset threshold value, and then the low-voltage starting control module is switched off.

2. The ultra-low input voltage DC/DC boost device of claim 1, wherein said low-voltage start-up control module comprises a detection control module, a charge pump module and a charge pump oscillator module; when the detection control module receives the reverse POK signal to control the start of the oscillator and the charge pump, the charge pump oscillator module is used for generating a periodic square wave signal and outputting the periodic square wave signal to the charge pump module to output a raised and periodic voltage signal CLKN, and when the detection control module receives the forward POK signal to control the stop of the oscillator and the charge pump.

3. The ultra-low input voltage DC/DC boosting device according to claim 2, wherein the low-voltage start-up control module further comprises a level shift module connected between the detection control module and the charge pump oscillator module for shifting a logic signal between different power supply voltages outputted from the detection control module.

4. The ultra low input voltage DC/DC boost device of claim 1, wherein the internal power supply module further comprises a power supply switching submodule that will switch to power an internal supply voltage V3 with a supply voltage V1 when the supply voltage V1 is greater than the supply voltage V2; when the supply voltage V2 is greater than the supply voltage V1, it is switched to supply the supply voltage V3 with the supply voltage V2.

5. The ultra-low input voltage DC/DC boost device according to claim 1, wherein said boost system drive control module comprises a LOGIC control module LOGIC and a drive module DRIVER, said LOGIC control module LOGIC receives said POK signal and PWM square wave signal output, if said received POK signal is forward POK, then generates a drive signal DR1 to said drive module DRIVER, said drive module DRIVER outputs a signal CLKP and a signal CLKN.

6. The ultra-low input voltage DC/DC boost device according to claim 1, wherein said internal power supply module further comprises a third transistor Q3 and a fourth transistor Q4; the source of the third transistor Q3 is connected to the voltage V1, the source of the fourth transistor Q4 is connected to the voltage V2, and the drains of the third transistor Q3 and the fourth transistor Q4 output the power voltage V3; when the voltage V2 is greater than the voltage V1, the power switching sub-module controls turning on the fourth transistor Q4 and turning off the third transistor Q3; when the voltage V2 is less than the voltage V1, the power switching sub-module controls turning on the third transistor Q3 and turning off the fourth transistor Q4; and the power supply OK submodule outputs the forward POK signal or the reverse POK signal according to the power supply voltage V3.

7. The ultra-low input voltage DC/DC boost device according to claim 1, wherein said PWM generation module comprises an error amplifier module EAMP, a slope compensation module, a reference voltage source module VREF, a PWM comparator module, and an oscillator OSC; the reference voltage source module is used for generating a constant voltage reference signal; the slope compensation module processes the periodic square wave signal into a RAMP signal; the oscillator module is used for generating a periodic square wave signal; the error amplifier module amplifies the difference value of VREF and a feedback signal FB of V2 and outputs a COMP signal; and the PWM comparator module compares the COMP signal with the RAMP signal and outputs a PWM square wave signal.

8. The ultra-low input voltage DC/DC boosting device according to claim 7, wherein the PWM generation module further comprises a first resistor RFB1 and a second resistor RFB2, the first resistor RFB1 and the second resistor RFB2 are connected in series between a supply voltage V2 and a ground terminal GND; the junction of the first resistor RFB1 and the second resistor RFB2 is the negative input terminal of the error amplifier module EAMP, and the positive input terminal of the error amplifier module EAMP is connected with the VREF signal generated by the reference voltage source module.

9. The ultra-low input voltage DC/DC booster device according to claim 1, further comprising a first capacitor C1 and a second capacitor C2, wherein the first capacitor C1 is connected in parallel between the input terminal of the DC power supply voltage V1 and a ground terminal GND; the second capacitor C2 is connected in parallel between the output terminal of the dc power voltage V2 and the ground terminal GND.

Technical Field

The invention belongs to the technical field of direct current booster circuit design, and relates to an ultra-low input voltage DC/DC booster device.

Background

At present, input voltage DC/DC boosting devices are more and more widely used, for example, they are often used in DC alkaline batteries, nickel-hydrogen rechargeable batteries, lithium-manganese batteries or lithium-ion rechargeable batteries, etc. which require DC boosting.

Referring to fig. 1, fig. 1 is a schematic diagram of an ultra-low input voltage DC/DC boost device in the prior art. The DC/DC booster device is used for outputting an output power supply voltage V2 which is equal to or higher than the input power supply voltage V1 after the input power supply voltage V1 is processed by the device.

As shown in fig. 1, the apparatus includes a Power Switch Control module (Power Switch), a Logic Inverter (INV), an Error Amplifier Module (EAMP), a PWM Comparator Module (CMP), a Logic Control module (PWM Control Logic), a driver module (DRVIER), a reference voltage source module (VREF), an oscillator module (OSC), a Slope compensation module (Slope compensation), a feedback resistor (RFB1, RFB2, RFB3, RFB4), a Power OK module (PowerOK), a P-type transistor (Q1, Q3, Q4), an N-type transistor (Q2), an inductor (L1), and a capacitor (C1, C2).

The power supply of the internal module of the start control circuit is a power supply voltage V3 which is respectively connected with one end of a P-type transistor Q3 and one end of a P-type transistor Q4, the other end of the P-type transistor Q3 and the other end of the P-type transistor Q4 are respectively connected with an input power supply voltage V1 and an output power supply voltage V2, and the power supply switching module judges the magnitude of the input power supply voltage V1 and the magnitude of the output power supply voltage V2 and outputs a judgment signal to control the on or off of the P-type transistor Q3 and the P-type transistor Q4, so that whether the input power supply voltage V1 or the output power supply voltage V2 of the power supply voltage V3 is supplied to the internal module is determined. The power supply V3 of the internal module is derived from the input supply voltage V1 when the input supply voltage V1 is greater than the output supply voltage V2, and the power supply V3 of the internal module is switched from the output supply voltage V2 when the output supply voltage V2 is greater than the input supply voltage V1.

That is, the power switching control module is used for switching the power supplies of the internal modules, and when the output power voltage V2 is greater than the input power voltage V1, the P-type transistor Q4 is turned on and the P-type transistor Q3 is turned off; when the output supply voltage V2 is less than the input supply voltage V1, the P-type transistor Q3 is turned on and the P-type transistor Q4 is turned off.

In addition, the internal modules in the control device can be started to work normally only when the power supply voltage V3 reaches a certain voltage value. When the supply voltage V3 meets the start-up voltage requirement, the reference voltage module preferably starts working and outputs a reference voltage VREF for the operation of the error amplifier, oscillator and comparator CMP comparison module. When the power supply OK module judges that the voltage of V3 is normal, a POK signal is output to the logic control module, and all modules in the device are controlled to start working; at this time, the output power voltage V2 is low, the FB signal obtained by voltage division of RFB1 and RFB2 is at a low value, the FB signal and the VREF signal are processed by the error amplifier module to output a COMP signal, the FB signal and the VREF signal are sent to one end of the PWM comparator module to be input, the FB signal and the VREF signal are compared with the periodic RAMP signal output by the oscillator module and the RAMP compensation module at the other end of the PWM comparator module to obtain a PWM square wave signal, the DR signal is processed by the logic control module to be output and provided to the driving module, the N-type transistor Q2 is turned on by the driving module output signal CLKN, a loop is formed between the input power voltage V1 and the ground terminal GND, at this time, the energy storage inductor L1 is charged with energy, then the driving module turns off the N-type transistor Q2, the P-type transistor Q1 is turned on, a loop is formed between the input power voltages V1 and V2, at this time, a current exists on the energy storage inductor L1, and a current cannot suddenly change, at this time, the voltage VL formed at the two ends of the inductor L1 and the input power voltage V1 transmit energy to the output power voltage V2 at the same time, so that the voltage of V2 rises, an FB signal obtained by dividing the voltage of the resistor RFB1 and the resistor RFB2 is greater than VREF, at this time, the error amplifier module and the PWM comparator module do not output a PWM square wave signal any more, the N-type transistor Q2 cannot be turned on, until the FB signal is less than VREF, the N-type transistor Q2 is turned on again to charge the energy storage inductor L1, and it is repeatedly ensured that the output power voltage V2 outputs a stable voltage. When the voltage of the power voltage V3 detected by the power OK module is lower than VREF, i.e., the power voltage is too low, the reverse signal of POK is output to the control logic module to turn off all modules in the device.

However, referring to fig. 2, the start-up control circuit has the following drawbacks:

when the boost device is started, the input power supply voltage V1 needs to be limited to work normally, and the excessively low input power supply voltage V1 can cause the modules in the circuit to work normally, so that the boost device can limit the application range of the input power supply voltage V1.

Disclosure of Invention

In order to solve the technical problems, the invention provides an ultra-low input voltage DC/DC boosting device, which has the following technical scheme:

an ultra-low input voltage DC/DC booster device is used for boosting an input direct-current power supply voltage V1 into a direct-current power supply voltage V2; the method comprises the following steps:

a first transistor Q1, a second transistor Q2, and an inductor L1; the inductor L1 is connected between the DC supply voltage V1 input and the first transistor Q1 and second transistor Q2 drain connection point SW; the source electrode of the first transistor Q1 is grounded, and the source electrode of the second transistor Q2 is connected with the output end of the direct current supply voltage V2; the internal power supply module is used for generating a power supply voltage V3 for supplying power to each module in the DC/DC booster device according to the power supply voltage V1 and the power supply voltage V2 and judging a power supply threshold of the power supply voltage V3; the power supply OK submodule is used for judging whether the power supply voltage V3 is greater than or equal to a preset threshold value, if so, outputting a forward POK signal, otherwise, outputting a reverse POK signal;

the PWM generating module generates a PWM square wave signal;

the boost system driving control module is used for controlling the grids of the first transistor Q1 and the second transistor Q2 according to the CLKP and the CLKN corresponding to the PWM square wave signal output signal if the received POK signal is positive POK according to the received PWM square wave signal and the POK signal; when the CLKN controls the second transistor Q2 to be turned on and the CLKP controls the first transistor to be turned off, a loop is formed between the power voltage V1 and the ground terminal GND, and at this time, the inductor L1 is charged to store energy; when the CLKN controls the second transistor Q2 to be turned off and the first transistor Q1 to be turned on, a loop is formed between the power voltages V1 and V2, and at this time, a current exists in the inductor L1, because the current in the inductor L1 cannot suddenly change the voltage difference VL formed at the two ends of the inductor L1, and the input power voltage V1 transmits energy to the output power voltage V2 at the same time, so that the voltage of V2 is raised;

and the low-voltage starting control module outputs a lifting and periodic voltage signal CLKN to drive the second transistor Q2 to be switched on and off according to the received reverse POK signal when the power supply voltage V3 does not reach the corresponding voltage threshold value, so that the power supply voltage V3 rises until the power supply OK submodule detects that the power supply voltage V3 reaches the preset threshold value, and then the low-voltage starting control module is switched off.

Further, the low-voltage starting control module comprises a detection control module, a charge pump module and a charge pump oscillator module; when the detection control module receives the reverse POK signal to control the start of the oscillator and the charge pump, the charge pump oscillator module is used for generating a periodic square wave signal and outputting the periodic square wave signal to the charge pump module to output a raised and periodic voltage signal CLKN, and when the detection control module receives the forward POK signal to control the stop of the oscillator and the charge pump.

Further, the low voltage start control module further comprises a level conversion module connected between the detection control module and the charge pump oscillator module, for converting logic signals between different power supply voltages output from the detection control module.

Further, the internal power supply module also includes a power supply switching submodule that will switch to supply the internal supply voltage V3 with the supply voltage V1 when the supply voltage V1 is greater than the supply voltage V2; when the supply voltage V2 is greater than the supply voltage V1, it is switched to supply the supply voltage V3 with the supply voltage V2.

Further, the boost system driving control module comprises a LOGIC control module LOGIC and a driving module DRIVER, wherein the LOGIC control module LOGIC receives the POK signal and the PWM square wave signal output, and if the received POK signal is forward POK, generates a driving signal DR1 to the driving module DRIVER, and the driving module DRIVER outputs a signal CLKP and a signal CLKN.

Further, the internal power supply module further includes a third transistor Q3 and a fourth transistor Q4; the source of the third transistor Q3 is connected to the voltage V1, the source of the fourth transistor Q4 is connected to the voltage V2, and the drains of the third transistor Q3 and the fourth transistor Q4 output the power voltage V3; when the voltage V2 is greater than the voltage V1, the power switching sub-module controls turning on the fourth transistor Q4 and turning off the third transistor Q3; when the voltage V2 is less than the voltage V1, the power switching sub-module controls turning on the third transistor Q3 and turning off the fourth transistor Q4; and the power supply OK submodule outputs the forward POK signal or the reverse POK signal according to the power supply voltage V3.

Further, the PWM generation module includes an error amplifier module EAMP, a slope compensation module, a reference voltage source module VREF, a PWM comparator module, and an oscillator OSC; the reference voltage source module is used for generating a constant voltage reference signal; the slope compensation module processes the periodic square wave signal into a RAMP signal; the oscillator module is used for generating a periodic square wave signal; the error amplifier module amplifies the difference value of VREF and a feedback signal FB of V2 and outputs a COMP signal; and the PWM comparator module compares the COMP signal with the RAMP signal and outputs a PWM square wave signal.

Further, the PWM generation module further includes a first resistor RFB1 and a second resistor RFB2, and the first resistor RFB1 and the second resistor RFB2 are connected in series between the power voltage V2 and the ground terminal GND; the junction of the first resistor RFB1 and the second resistor RFB2 is the negative input terminal of the error amplifier module EAMP, and the positive input terminal of the error amplifier module EAMP is connected with the VREF signal generated by the reference voltage source module.

Further, the ultra-low input voltage DC/DC boost device further comprises a first capacitor C1 and a second capacitor C2, wherein the first capacitor C1 is connected in parallel between the input end of the DC power supply voltage V1 and the ground end GND; the second capacitor C2 is connected in parallel between the output terminal of the dc power voltage V2 and the ground terminal GND.

According to the technical scheme, the ultra-low input voltage DC/DC booster device can effectively solve the limitation of the booster device on the requirement of the input power supply voltage V1, namely the input power supply voltage V1 can ensure that the DC/DC booster device is normally started and works normally under the condition of ultra-low voltage.

Drawings

FIG. 1 is a schematic diagram of an ultra-low input voltage DC/DC booster device in the prior art

FIG. 2 is a schematic diagram showing waveforms of a power supply voltage V1 and a power supply voltage V2 in the prior art and the embodiment of the present invention

FIG. 3 is a schematic diagram of an ultra-low input voltage DC/DC booster according to an embodiment of the present invention

FIG. 4 is a schematic circuit diagram of a detection control module according to an embodiment of the present invention

FIG. 5 is a schematic diagram of an ultra-low input voltage DC/DC booster according to another preferred embodiment of the present invention

Detailed Description

The following describes the embodiments of the present invention in further detail with reference to fig. 2-5.

It should be noted that the greatest difference between the present invention and the prior art is: in the starting control circuit of the low-input-voltage DC/DC boosting device, the starting control circuit is used for boosting an input direct-current power supply voltage V1 into a direct-current power supply voltage V2, and is additionally provided with a starting control module so as to realize the starting of the ultralow V1 voltage. That is, when the system operates under the condition that the input power voltage V1 is at an ultra-low voltage, the normal start and normal operation of the DC/DC booster device can be ensured, therefore, the invention can effectively solve the limitation of the booster device on the requirement of the input power voltage V1.

Example 1

Referring to fig. 3, fig. 3 is a schematic diagram of an ultra-low input voltage DC/DC boost device according to a preferred embodiment of the present invention. As shown in fig. 3, the low input voltage DC/DC boost apparatus includes a first voltage-dividing resistor RFB1, a second voltage-dividing resistor RFB2, a voltage-stabilizing capacitor C1 for a power voltage V1, a voltage-stabilizing capacitor C2 for a power voltage V2, an inductor L1, a first transistor Q1, a second transistor Q2, an internal power supply module, a PWM generation module, a boost system driving control module, and a low-voltage start control module; the power supply voltage V1 is a voltage signal at the input of the control circuit, the power supply voltage V2 is a voltage signal at the output of the control circuit, and the voltage V1 is generally lower than the voltage V2.

Specifically, in the following embodiments of the present invention, the inductor L1 is connected between the dc supply voltage V1 input terminal and the drain connection point SW of the first transistor Q1 and the second transistor Q2; the source of the first transistor Q1 is grounded, and the source of the second transistor Q2 is connected to the output terminal of the dc power supply voltage V2. The first capacitor C1 is connected in parallel between the input end of the DC power supply voltage V1 and the ground end GND; the second capacitor C2 is connected in parallel between the output terminal of the dc power voltage V2 and the ground terminal GND.

The internal power supply module is used for generating a power supply voltage V3 for supplying power to each module in the DC/DC boosting device according to a power supply voltage V1 and a power supply voltage V2. The internal power module may include a third transistor Q3, a fourth transistor Q4, a power OK submodule, and a power switching submodule. In the embodiment of the invention, the source of the fourth transistor Q4 is connected to the voltage V2, and the drains of the third transistor Q3 and the fourth transistor Q4 output the power voltage V3.

Specifically, when the supply voltage V2 is greater than the supply voltage V1, switching to supply the supply voltage V3 with the supply voltage V2; the power switching sub-module controls the fourth transistor Q4 to be turned on and the third transistor Q3 to be turned off.

When the supply voltage V2 is less than the supply voltage V1, the power switching submodule will switch to power the internal supply voltage V3 with the supply voltage V1 and charge the inductance L1 when the supply voltage V1 is greater than the supply voltage V2. Namely, the power supply switching submodule controls to turn on the third transistor Q3 and turn off the fourth transistor Q4; and the power supply OK submodule outputs the forward POK signal or the reverse POK signal according to the power supply voltage V3. That is, the power OK submodule is configured to determine whether the power voltage V3 is greater than or equal to a predetermined threshold, and if so, output a forward POK signal, otherwise, output a reverse POK signal.

The PWM generation module comprises an error amplifier module EAMP, a slope compensation module, a reference voltage source module VREF, a first resistor RFB1, a second resistor RFB2, a PWM comparator module and an oscillator OSC; the first resistor RFB1 and the second resistor RFB2 are connected in series between a power supply voltage V2 and a ground terminal GND; the junction of the first resistor RFB1 and the second resistor RFB2 is the negative input terminal of the error amplifier module EAMP, and the positive input terminal of the error amplifier module EAMP is connected with the VREF signal generated by the reference voltage source module.

The reference voltage source module is used for generating a constant voltage reference signal; the slope compensation module processes the periodic square wave signal into a RAMP signal; the oscillator module OSC is used for generating a periodic square wave signal; the error amplifier module amplifies the difference value of VREF and a feedback signal FB of V2 and outputs a COMP signal; and the PWM comparator module compares the COMP signal with the RAMP signal and outputs a PWM square wave signal.

The boost system drive control module comprises a LOGIC control module LOGIC and a drive module DRIVER, wherein the LOGIC control module LOGIC receives the POK signal and the PWM square wave signal output, if the received POK signal is forward POK, a drive signal DR1 is generated to the drive module DRIVER, and the drive module DRIVER outputs a signal CLKP and a signal CLKN.

In the embodiment of the present invention, the added low-voltage start control module may output a raised and periodic voltage signal CLKN to drive the second transistor Q2 to be turned on and off according to the received reverse POK signal when the power voltage V3 does not reach the corresponding voltage threshold, so as to raise the power voltage V3, and turn off the low-voltage start control module until the power OK submodule detects that the power voltage V3 reaches the predetermined threshold.

As shown in fig. 3, the low-voltage start Control module includes a Sense Control module (Sense Control), a Charge Pump module (Charge Pump), and a Charge Pump oscillator module (OSC Pump).

When the detection control module receives the reverse POK signal to control the start of the charge pump oscillator module and the charge pump, the charge pump oscillator module is used for generating a periodic square wave signal and outputting the periodic square wave signal to the charge pump module to output a raised and periodic voltage signal CLKN, and when the detection control module receives the forward POK signal to control the close of the oscillator OSC and the charge pump module.

Referring to fig. 4 in conjunction with fig. 3, fig. 4 is a circuit diagram of a detection control module according to an embodiment of the invention. As shown in fig. 4, when the voltage boost device is started, the power supply voltage V2 is less than the power supply voltage V1, the power supply switching module switches the internal power supply V3 from the power supply voltage V1 at this time, and the feedback signal of the internal power supply V3 is determined by the PWM comparator module to be insufficient to enable the normal operation of the voltage boost device system, the detection control module outputs the ENPUMP signal to enable the charge pump oscillator module and the charge pump module to start operating, the charge pump oscillator outputs a periodic square wave signal to enable the charge pump module to operate, a boosted voltage signal CLKN is output to drive the second transistor Q2 (shown as an N-type transistor) to be turned on, a current loop is formed between the power supply voltage V1 and the ground terminal to charge and store energy in the energy storage inductor L1, and at this time, the current detected by the third transistor Q3 (shown as an N-type transistor) in the detection control module is in a certain proportion to the current of the second transistor Q2, a current detected by the third transistor and a constant current source I_biasThe comparison is performed to determine whether the current of the third transistor Q3 reaches the set value.

When the set current value is reached, the reverse signal of ENPUMP is output to close the charge pump oscillator module OSC and the charge pump module, CLKN signal closes the second transistor Q2, the first transistor Q1 is opened, the current exists on the energy storage inductor L1 at the moment, the current of the inductor L1 cannot change suddenly, a current loop is formed between the power supply voltage V1 and the power supply voltage V2, the voltage VL formed at the two ends of the inductor L1 and the power supply voltage V1 transmit energy to the power supply voltage V2 at the same time, so that the power supply voltage V2 rises, when the power supply voltage V2 is greater than the power supply voltage V1, the power supply switching module switches the internal power supply V3 from the power supply voltage V2, and if the feedback signal of the internal power supply V3 is judged by the PWM comparator module and then the booster system still cannot work normally, the detection control module continues to output ENPUMP signal to restart the charge pump and the charge pump, and when the power supply OK module outputs a POK signal which can enable the boosting device to normally work after judging that the voltage of the internal power supply V3 is normal, the detection control module, the charge pump oscillator module and the charge pump module are closed, and meanwhile, the effect of saving energy can be achieved.

Example 2

Based on the foregoing embodiment 1, the DC/DC boost device is started at the ultra-low V1 voltage, however, since the detection control module consumes a large amount of current, when the voltage V1 is at the ultra-low voltage, the third transistor Q3 (shown as a P-type transistor) is in a critical on state to form a large resistor, and the current at this time flows from the power voltage V1 to the power voltage V3 via the third transistor Q3 to form a large voltage drop on the power voltage V3, and the ultra-low voltage of the power voltage V3 causes the detection and determination module and other modules to work abnormally, resulting in functional failure.

Therefore, in the embodiment of the present invention, the power supply voltage V1 is introduced to supply power to the detection and determination module, so that the detection and determination module outputs the determination signal normally, and then the Level Shift module (Level Shift) outputs the processed ENPUMP signal to the charge pump oscillator and the charge pump to operate.

Referring to fig. 5, fig. 5 is a schematic diagram illustrating an ultra-low input voltage DC/DC boost device according to another preferred embodiment of the present invention. As shown in fig. 5, the low-voltage start Control module includes a sensing Control module (Sense Control), a Level Shift module (Level Shift), a Charge Pump module (Charge Pump), and a Charge Pump oscillator module (OSC Pump) for starting the ultra-low power voltage V1.

The charge pump oscillator module generates periodic square wave signals and outputs the periodic square wave signals to the charge pump module; the charge pump module is used for outputting a lifting overvoltage driving signal; the detection control module is used for controlling the switches of the oscillator and the charge pump; the level conversion module is used for converting logic signals between different power supply voltages.

Similarly, other specific circuits in embodiment 1 can also be introduced into embodiment 2, and are not described herein again.

It should be noted that, referring to fig. 2 again, the start-up of the boosting device in the prior art has a certain requirement for the lowest V1 voltage, but the invention can break through the limitation of the prior art on the lowest power voltage V1, and can ensure the normal start-up of the boosting device even at the lower power voltage V1.

The above description is only for the preferred embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, so that all the equivalent structural changes made by using the contents of the description and the drawings of the present invention should be included in the scope of the present invention.