阅读说明：本技术 电荷泵电路及电子设备 (Charge pump circuit and electronic equipment ) 是由 王肖 于 2020-06-16 设计创作，主要内容包括：本发明实施例涉及集成电路领域,公开了一种电荷泵电路及电子设备。本发明中,通过设置第一比较器,将供电单元与第一电荷泵的输出端分别连接第一比较器的第一输入端、第二输入端,从而可以通过第一比较器比较供电单元与第一电荷泵输出端的电压的大小,且将两者中较大的电压作为第一电荷泵的输入电压,且当第一电荷泵的输出端的电压大于第一电荷泵的输入端电压时,形成一个反馈环路,使得第一电荷泵的输入端电压增大,而根据MOS管的特性可知,电压越大,电阻越小,损耗也就越少；因此,通过本申请的电路可以在供电单元的电压不变的情况下,降低电荷泵的损耗,提高了电荷泵整体的工作效率。(The embodiment of the invention relates to the field of integrated circuits, and discloses a charge pump circuit and electronic equipment. According to the invention, the power supply unit and the output end of the first charge pump are respectively connected with the first input end and the second input end of the first comparator by arranging the first comparator, so that the voltage of the output ends of the power supply unit and the first charge pump can be compared by the first comparator, the larger voltage of the output ends of the power supply unit and the first charge pump is taken as the input voltage of the first charge pump, and when the voltage of the output end of the first charge pump is larger than the voltage of the input end of the first charge pump, a feedback loop is formed, so that the voltage of the input end of the first charge pump is increased, and according to the characteristics of an MOS (metal oxide semiconductor) transistor, the larger voltage is, the smaller resistance is, and the lower loss is; therefore, the circuit can reduce the loss of the charge pump and improve the overall working efficiency of the charge pump under the condition that the voltage of the power supply unit is not changed.)

1. A charge pump circuit, comprising: the charge pump circuit comprises a first charge pump, a first comparator, a first switch and a second switch;

the input end of the first charge pump is connected with a first power supply end of a power supply unit through the first switch;

the output end of the first charge pump is connected with the input end of the first charge pump through the second switch;

a first input end of the first comparator is connected with the power supply unit, a second input end of the first comparator is connected with an output end of the first charge pump, and an output end of the first comparator is connected with the first switch and the second switch;

the first comparator is used for controlling the first switch to be switched off and the second switch to be switched on when the voltage of the first input end is smaller than the voltage of the second input end, and controlling the first switch to be switched on and the second switch to be switched off when the voltage of the first input end is larger than the voltage of the second input end.

2. The charge pump circuit of claim 1, further comprising a second comparator, a frequency translation unit;

a first input end of the second comparator is connected with an output end of the first charge pump, a second input end of the second comparator is connected with an external reference voltage, and an output end of the second comparator is connected with the frequency conversion unit; the second comparator is used for starting the frequency conversion unit when the voltage of the output end of the first charge pump is smaller than the preset reference voltage of the external reference voltage;

the input end of the frequency conversion unit is connected with the second power supply end of the power supply unit, and the output end of the frequency conversion unit is connected with the input end of the first charge pump;

the frequency conversion unit is used for generating a control frequency and inputting the control frequency to the input end of the first charge pump when the frequency conversion unit is started.

3. The charge pump circuit of claim 2, wherein the frequency translation unit comprises a second charge pump, a voltage controlled oscillator;

the input end of the second charge pump is connected with the second power supply end of the power supply unit, the output end of the second charge pump is connected with the input end of the voltage-controlled oscillator, and the output end of the voltage-controlled oscillator is connected with the input end of the first charge pump;

the second charge pump is used for generating a control voltage; the control voltage is positively correlated with the difference between the output voltage of the first charge pump and the preset reference voltage;

the voltage-controlled oscillator is used for generating the control frequency according to the control voltage and inputting the control frequency to the input end of the first charge pump.

4. The charge pump circuit of claim 3, wherein the frequency translation unit further comprises a filter;

the filter is disposed between the second charge pump and the voltage controlled oscillator.

5. The charge pump circuit of claim 1, wherein the first switch and the second switch are one single-pole double-throw switch; the fixed end of the single-pole double-throw switch is connected with the input end of the first charge pump, the first moving end of the single-pole double-throw switch is connected with the power supply unit, and the second moving end of the single-pole double-throw switch is connected with the output end of the first charge pump.

6. An electronic device comprising the charge pump circuit of any of claims 1 to 5.

Technical Field

Embodiments of the present invention relate to the field of integrated circuits, and in particular, to a charge pump circuit and an electronic device.

Background

The charge pump is a DC-DC converter, mainly uses capacitor as energy storage element to generate output voltage larger than input voltage, the electric efficiency of the charge pump circuit is very high, and the circuit structure is simpler, and it has wide application in production. The charge pump circuit structure commonly adopted in the prior art is that a capacitor and an MOS (metal oxide semiconductor) switching tube are arranged, and the capacitor is continuously switched between two states of charging and discharging through the connection and disconnection of the MOS switching tube, so that the high-voltage output of the output end of the charge pump is realized.

The inventor finds that at least the following problems exist in the prior art: the MOS switch tube has resistance in a conducting state, and the smaller the input voltage is, the larger the resistance value is, the higher the loss of the charge pump is, thereby influencing the working efficiency of the charge pump.

Disclosure of Invention

Embodiments of the present invention provide a charge pump circuit and an electronic device, so that under the condition that the voltage of a power supply unit is not changed, the loss of a MOS switch tube in the charge pump is reduced, and the working efficiency of the charge pump is improved.

To solve the above technical problem, an embodiment of the present invention provides a charge pump circuit, including: the charge pump circuit comprises a first charge pump, a first comparator, a first switch and a second switch; the input end of the first charge pump is connected with a first power supply end of a power supply unit through the first switch; the output end of the first charge pump is connected with the input end of the first charge pump through the second switch; a first input end of the first comparator is connected with the power supply unit, a second input end of the first comparator is connected with an output end of the first charge pump, and an output end of the first comparator is connected with the first switch and the second switch; the first comparator is used for controlling the first switch to be switched off and the second switch to be switched on when the voltage of the first input end is smaller than the voltage of the second input end, and controlling the first switch to be switched on and the second switch to be switched off when the voltage of the first input end is larger than the voltage of the second input end.

The embodiment of the invention also provides electronic equipment which comprises the charge pump circuit.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

FIG. 1 is a schematic circuit diagram of a typical boost charge pump according to the prior art

Fig. 2 and fig. 3 are schematic structural diagrams of a charge pump circuit according to a first embodiment of the present invention;

FIG. 4 is a schematic diagram of a second comparator according to a second embodiment of the present invention;

FIG. 5 is a schematic diagram of a portion of a charge pump circuit according to a second embodiment of the present invention;

fig. 6 is a schematic diagram of a structure of a frequency conversion unit according to a second embodiment of the present invention;

fig. 7 is a schematic diagram of the structure of a filter according to a second embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that in various embodiments of the invention, numerous technical details are set forth in order to provide a better understanding of the present application. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not constitute any limitation to the specific implementation manner of the present invention, and the embodiments may be mutually incorporated and referred to without contradiction.

The numbering of the elements herein, such as first, second, etc., is used solely to distinguish between the elements as described and not necessarily in any sequential or technical sense. References herein to connection or coupling, unless otherwise indicated, include both direct and indirect connections (couplings).

As shown in fig. 1, which is a schematic diagram of a typical circuit structure of a boost charge pump in the prior art, CK and CKN are both MOS transistors; in the working process, firstly, the CK switch is turned on, charges are injected into Cp through Vin, then, the CK switch is turned off and the CKN switch is turned on, the charges stored in Vin and Cp are pushed to Vout to achieve the boosting effect, and theoretically, the output voltage can reach Vout which is 2 Vin. However, since CK and CKN are MOS switch tubes, and there is a resistance in the working process of CK and CKN, the smaller the output voltage Vout is, and the smaller the voltage Vin is, the larger the resistance of CK and CKN is; therefore, in the prior art, when Vin is low, the losses of CK and CKN are high, and the working efficiency of the charge pump is low.

In order to reduce the loss of the charge pump and improve the overall operating efficiency of the charge pump without changing the voltage of the power supply unit, a first embodiment of the present invention relates to a charge pump circuit, as shown in fig. 2 and 3, the charge pump circuit of this embodiment includes a first charge pump 101, a first comparator 102, a first switch S1, and a second switch S2.

Specifically, referring to fig. 2, the input terminal a of the first charge pump 101 is connected to the first power supply terminal a of the power supply unit 103 through the first switch S1; the output terminal B of the first charge pump 101 is connected to the input terminal a of the first charge pump 101 through the second switch S2; the output end B of the first charge pump 101 may be connected to an external load through a point C to supply power to the external load.

With continued reference to fig. 3, a first input terminal D of the first comparator 102 is connected to the power supply unit 103, a second input terminal E of the first comparator is connected to the output terminal B of the first charge pump 101, and an output terminal F of the first comparator 102 is connected to the first switch S1 and the second switch S2; the first comparator 102 is used for controlling the first switch S1 to be opened and the second switch S2 to be closed when the voltage of the first input terminal D is less than the voltage of the second input terminal E, and controlling the first switch S1 to be closed and the second switch S2 to be opened when the voltage of the first input terminal D is greater than the voltage of the second input terminal E.

Specifically, since the output terminal F of the first comparator 102 is connected to the first switch S1 and the second switch S2, the output terminal F of the first comparator 102 outputs a control signal for controlling the first switch S1 and the second switch S2 to be closed or turned on; therefore, in the present embodiment, when the voltage of the first input terminal D is less than the voltage of the second input terminal E, the first control signal output by the output terminal F of the first comparator 102 controls the first switch S1 to be opened and the second switch S2 to be closed; when the voltage of the first input terminal D is greater than the voltage of the second input terminal E, the second control signal output by the output terminal F of the first comparator 102 controls the first switch S1 to be closed, and the second switch S2 to be opened.

In one example, the first switch S1 and the second switch S2 can be configured as a single pole double throw switch; the fixed end of the single-pole double-throw switch is connected with the input end of the first charge pump, the first moving end of the single-pole double-throw switch is connected with the power supply unit, and the second moving end of the single-pole double-throw switch is connected with the output end of the first charge pump. By setting the first switch and the second switch as a single-pole double-throw switch, the single-pole double-throw switch simultaneously conducts only one end, and the situation that the output ends of the power supply unit and the first charge pump are simultaneously connected to the input end of the first charge pump is avoided.

In practical applications, the circuit structure of the first charge pump is the charge pump circuit structure shown in fig. 1, and as shown in the charge pump structure shown in fig. 1, CK and CKN are continuously switched under the action of Vin, so as to realize the conversion from low voltage to high voltage.

In this embodiment, by providing the first comparator, the output ends of the power supply unit and the first charge pump are respectively connected to the first input end and the second input end of the first comparator, so that the voltages at the output ends of the power supply unit and the first charge pump can be compared by the first comparator, and the larger voltage of the power supply unit and the first charge pump is used as the input voltage of the first charge pump, and when the voltage at the output end of the first charge pump is greater than the voltage at the input end of the first charge pump, a feedback loop is formed, so that the voltage at the input end of the first charge pump is increased, and according to the characteristics of the MOS transistor, the larger the voltage is, the smaller the resistance is, and the smaller the loss is; therefore, the circuit can reduce the loss of the charge pump and improve the overall working efficiency of the charge pump under the condition that the voltage of the power supply unit is not changed.

A second embodiment of the present invention relates to a charge pump circuit. The second embodiment is substantially the same as the first embodiment, with the main differences being: in a second embodiment, the charge pump circuit further includes a second comparator, a frequency translation unit. Fig. 5 shows a schematic diagram of a part of a structure of the charge pump circuit in this embodiment, and for convenience of describing a circuit connection relationship, this embodiment will be described in detail with reference to fig. 2 and 4 in the first embodiment, where the charge pump circuit in this embodiment further includes: a second comparator 104, and a frequency conversion unit 105.

Specifically, as shown in fig. 4, it is a schematic structural diagram of the second comparator 104 in the present embodiment, wherein a first input terminal G of the second comparator 104 is connected to an output terminal B of the first charge pump 101, a second input terminal H of the second comparator 104 is connected to an external reference voltage, and an output terminal M of the second comparator 104 is connected to the frequency conversion unit 105; the second comparator 104 is configured to turn on the frequency conversion unit 105 when the voltage at the output terminal B of the first charge pump 101 is lower than a preset reference voltage of the external reference voltage; that is, when the voltage at the output terminal B of the first charge pump 101 is less than the predetermined reference voltage of the external reference voltage, the second comparator 104 generates a control signal, and the control signal is transmitted to the frequency conversion unit 105 through the output terminal M of the second comparator 104, so that the frequency conversion unit 105 starts to operate normally.

Specifically, the output terminal J of the frequency conversion unit 105 is connected to the second power supply terminal b of the power supply unit 103; the frequency conversion unit 105 is used for generating a control frequency and inputting the control frequency to the input terminal a of the first charge pump 101 when being turned on.

In practical applications, the first power supply terminal a and the second power supply terminal b of the power supply unit 103 may be a port, wherein the frequency conversion unit 105 and the input terminal a of the first charge pump 101 are respectively connected to the port of the power supply unit 103, so as to ensure that the power supply unit 103 can supply both power to the first charge pump 101 and power to the frequency conversion unit 105.

In practical application, when the voltage at the output end of the first charge pump is smaller than the preset reference voltage of the external reference voltage, it indicates that the current voltage at the output end of the first charge pump cannot continuously support driving the load.

In one example, the frequency conversion unit 105 includes a second charge pump, a voltage controlled oscillator. As shown in fig. 6, which is a schematic diagram of the frequency conversion unit 105, the frequency conversion unit 105 includes a second charge pump 1051 and a voltage-controlled oscillator 1052; an input terminal of the second charge pump 1051 is used as an input terminal I of the frequency conversion unit 105 and is connected to the second power supply terminal b of the power supply unit 103, an output terminal of the second charge pump 1051 is connected to an input terminal of the voltage-controlled oscillator 1052, and an output terminal of the voltage-controlled oscillator 1052 is used as an output terminal J of the frequency conversion unit 105 and is connected to an input terminal of the first charge pump 101. Specifically, the second charge pump 1051 is used to generate a control voltage; the control voltage is positively correlated with the difference between the output voltage of the first charge pump 101 and the preset reference voltage.

Specifically, the voltage-controlled oscillator 1052 is configured to generate a control frequency according to the control voltage and input the control frequency to the input terminal a of the first charge pump 101.

In practical applications, the output end M of the second comparator 104 is specifically connected to the second charge pump 1051 in the frequency conversion unit 105, and when the voltage of the output end B of the first charge pump 101 is smaller than the preset reference voltage of the external reference voltage, the second comparator 104 generates a control signal, and the control signal is transmitted to the second charge pump 1051 through the output end M of the second comparator 104, so that the second charge pump 1051 starts to operate normally and generates the control voltage.

In one example, the frequency transform unit 105 further includes a filter; the filter is arranged between the second charge pump 1051 and the voltage controlled oscillator 1052. Through setting up the wave filter for when the control voltage that the second charge pump generated passes through the wave filter, the signal of other frequencies of filtering improves the smoothness degree of control voltage waveform. In this embodiment, the filter is a low-pass filter, and the circuit structure of the filter is shown in fig. 7, and the filter in this embodiment is composed of a resistor R and two capacitors C, wherein an input terminal K of the filter is connected to the output terminal of the second charge pump 1051, and an output terminal L of the filter is connected to the input terminal of the voltage-controlled oscillator 1052.

A fourth embodiment of the present invention relates to an electronic device including the charge pump circuits of the first and second embodiments described above.

In this embodiment, the charge pump circuits in the first and second embodiments of the circuit can reduce the loss of the electronic device and improve the working efficiency of the electronic device under the condition that the voltage of the power supply unit is not changed.

It should be noted that each unit in the present embodiment may be one physical unit, may be a part of one physical unit, or may be implemented by a combination of a plurality of physical units. In addition, in order to highlight the innovative part of the present invention, elements that are not so closely related to solving the technical problems proposed by the present invention are not introduced in the present embodiment, but this does not indicate that other elements are not present in the present embodiment.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific embodiments for practicing the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.