CN103178709B - Charge pump circuit and sequential control method thereof - Google Patents

Abstract

The present invention relates to a charge pump circuit and its timing control method. The charge pump circuit includes: a first pumping capacitor, a second pumping capacitor, a power port (Vcc), a ground port (GND), and an output port (Vout). and multiple timing switches. The power port and the output port are respectively connected in parallel to the first end of the first pumping capacitor through a timing switch, and the power port and the ground port are respectively connected in parallel to the first end of the first pumping capacitor through a timing switch. The second end; the power port and the output port are respectively connected in parallel to the first end of the second pumping capacitor through a timing switch, and the power port and the ground port are respectively connected in parallel to the second pumping capacitor through a timing switch. The second end of the pumping capacitor; the first end of the first pumping capacitor is electrically connected in series with the first end of the second pumping capacitor through a timing switch. The invention adopts the alternate output of two pumping capacitors and the charge recovery mechanism to reduce circuit energy consumption and output ripple.

Description

Charge pump circuit and its timing control method

technical field

The invention relates to a charge pump circuit, in particular to a charge pump circuit and a timing control method thereof.

Background technique

The charge pump circuit is a DC-DC circuit that can generate an output voltage higher than the input power supply voltage as the operating voltage of other circuit modules. At present, the charge pump circuit is widely used in the fields of non-volatile memory and TFTLCD driver, and the ripple size of the output voltage and the energy efficiency of the circuit have become important indicators to measure the performance of the charge pump. The current triple voltage charge pump circuit usually uses two flying capacitors and two-phase non-overlapping timing signals, and uses the series connection of two capacitors to realize the output of three times the power supply voltage, as shown in FIG. 1 . However, there are some problems with this circuit. When the circuit generates three times the power supply voltage, a switch needs to be used to connect two capacitors in series, which will increase the energy loss of the charge pump circuit for external output. In addition, the circuit only generates an output voltage that is three times the supply voltage in the output phase, and the output voltage can only be maintained by the load capacitance in its charging phase, which will cause a large ripple in the output voltage.

Contents of the invention

In view of the above-mentioned problems in the prior art, an object of the present invention is to provide a charge pump circuit with low energy consumption and optimized output ripple. To achieve the above purpose, the present invention proposes a charge pump circuit and a control method thereof.

A charge pump proposed by the present invention includes: a first pumping capacitor, a second pumping capacitor, a power port (Vcc), a ground port (GND), an output port (Vout), and a plurality of sequential switches; the power port The output port is respectively connected in parallel to the first end of the first pumping capacitor through a timing switch, and the power port and the ground port are respectively connected in parallel to the second end of the first pumping capacitor through a timing switch; The power supply port and the output port are respectively connected in parallel to the first end of the second pumping capacitor through a timing switch, and the power supply port and the ground port are respectively connected in parallel to the first end of the second pumping capacitor through a timing switch. The second end: the first end of the first pumping capacitor is electrically connected in series with the first end of the second pumping capacitor through a timing switch.

Preferably, the timing switch includes:

The first timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the first timing switch receives the third timing signal, and the first terminal of the first timing switch is electrically connected to the first the first end of the pumping capacitor, the second end of the first timing switch is electrically connected to the first end of the second pumping capacitor;

The second timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the second timing switch receives the first timing signal, and the first terminal of the second timing switch is electrically connected to the power port , the second end of the second timing switch is electrically connected to the first end of the first pumping capacitor;

The third timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the third timing switch receives the sixth timing signal, and the first terminal of the third timing switch is electrically connected to the ground port , the second end of the third timing switch is electrically connected to the second end of the first pumping capacitor;

The fourth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the fourth timing switch receives the second timing signal, and the first terminal of the fourth timing switch is electrically connected to the power port , the second end of the fourth timing switch is electrically connected to the first end of the second pumping capacitor;

The fifth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the fifth timing switch receives the seventh timing signal, and the first terminal of the fifth timing switch is electrically connected to the ground port , the second end of the fifth timing switch is electrically connected to the second end of the second pumping capacitor;

The sixth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the sixth timing switch receives the second timing signal, and the first terminal of the sixth timing switch is electrically connected to the output port , the second end of the sixth timing switch is electrically connected to the first end of the first pumping capacitor;

The seventh timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the seventh timing switch receives the fifth timing signal, and the first terminal of the seventh timing switch is electrically connected to the power port , the second terminal of the seventh timing switch is electrically connected to the second terminal of the first pumping capacitor;

The eighth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the eighth timing switch receives the first timing signal, and the first terminal of the eighth timing switch is electrically connected to the output port , the second end of the eighth timing switch is electrically connected to the first end of the second pumping capacitor;

The ninth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the ninth timing switch receives the fourth timing signal, and the first terminal of the ninth timing switch is electrically connected to the power port , the second terminal of the ninth timing switch is electrically connected to the second terminal of the second pumping capacitor. .

Preferably, the first timing signal and the second timing signal are a first group of two-phase non-overlapping timing signals; the fourth timing signal and the fifth timing signal are a second group of two-phase non-overlapping timing signals A timing signal; the sixth timing signal and the seventh timing signal are a third group of two-phase non-overlapping timing signals; the third timing signal is non-overlapping with the first group of two-phase non-overlapping timing signals.

Preferably, the two falling edges of the second group of two-phase non-overlapping timing signals are respectively synchronized with the two falling edges of the first group of two-phase non-overlapping timing signals, and the two rising edges are respectively relative to the The two rising edges of the first group of two-phase non-overlapping timing signals are delayed by a certain time to include the effective phase of the third timing signal, and the delay time does not exceed the first group of two-phase non-overlapping timing signals. Non-overlapping time for overlapping timing signals.

Preferably, the third group of two-phase non-overlapping timing signals are respectively inversion signals of the second group of two-phase non-overlapping timing signals.

Preferably, the first pumping capacitor is the same as the second pumping capacitor.

Preferably, the power port (Vcc), the ground port (GND) and the output port (Vout) are respectively one or more.

Preferably, the first timing switch is a single PMOS transistor or a single NMOS transistor or a transmission gate; the third timing switch and the fifth timing switch are N-type MOS transistors; the second timing switch, the fourth timing switch , the sixth timing switch, the seventh timing switch, the eighth timing switch and the ninth timing switch are P-type MOS transistors.

The present invention also provides a timing control method for a charge pump circuit, which is used to control the charge pump circuit, including the following process: charging and discharging process, using the first pumping capacitor as a charging capacitor in the Nth timing cycle, so that The second pumping capacitor is used as the discharge capacitor to output the voltage externally, and the second pumping capacitor is used as the charging capacitor in the N+1th timing cycle, and the first pumping capacitor is used as the discharge capacitor to output the voltage externally, and the discharge capacitor is When the first terminal is discharging, the power supply voltage is added to the second terminal of the discharge capacitor so that the first terminal of the discharge capacitor obtains a multiplied voltage; the charge recovery process, after the discharge capacitor of the Nth timing cycle is output to the outside Before the discharge capacitor of the N+1th timing cycle is output to the outside, the second end of the discharge capacitor of the Nth timing cycle is turned on with the power port, so that the charging of the Nth timing cycle The second end of the capacitor is connected to the ground port, and at the same time, the first end of the discharge capacitor in the Nth timing cycle is electrically connected to the first end of the discharge capacitor in the N+1th timing cycle. , so that the charge is transferred from the first end of the discharge capacitor in the Nth time sequence cycle to the first end of the discharge capacitor in the N+1th time sequence cycle to obtain a recovery voltage; during the voltage output process, the recovery voltage and the said recovery voltage After the multiplied voltage is superimposed, it is output from the discharge capacitor of the N+1th timing cycle.

Preferably, the charging process of the first pumping capacitor is performed simultaneously with the discharging process of the second pumping capacitor; the discharging process of the first pumping capacitor is performed simultaneously with the charging and discharging process of the second pumping capacitor conduct.

Preferably, the charge recovery process is performed after the discharge process of the Nth timing cycle and before the discharge process of the N+1th timing cycle.

Preferably, the charging and discharging process in the Nth timing cycle includes: the charging process of the first pumping capacitor and the discharging process of the second pumping capacitor, wherein the Nth timing cycle at the same time is provided before the end of the effective phase The first timing signal, the fourth timing signal, and the sixth timing signal make the second timing switch, the third timing switch, the eighth timing switch, and the ninth timing switch in the conduction state respectively, and at the same time provide other timing signals in invalid phases to enable The other timing switches are in the off state; the charge recovery process is the charge recovery process of the first pumping capacitor in the Nth timing cycle, wherein when the first timing signal enters the inactive phase, the third in the active phase is provided Timing signal, at the same time provide the fourth timing signal and the sixth timing signal in the effective phase to make the first timing switch, the ninth timing switch, and the third timing switch in the conduction state, and provide other timing signals in the invalid phase to make the other The timing switch is in the closed state; the voltage output process is the discharge process of the second pumping capacitor in the Nth timing cycle; the charging and discharging process includes: the first pumping capacitor in the N+1 timing cycle The discharge process and the charging process of the second pumping capacitor, wherein at the beginning of the N+1th timing period, the second timing signal, the fifth timing signal and the seventh timing signal that are simultaneously in the effective phase are provided to make the sixth timing switch , the seventh timing switch, the fourth timing switch and the fifth timing switch are in the on state, and at the same time, other timing signals in the invalid phase are provided to make the other timing switches in the off state; the charge recovery process is at the N+1 timing cycle The middle is the charge recovery process of the second pumping capacitor, wherein when the second timing signal enters the invalid phase, the third timing signal entering the valid phase is provided again, and the fifth timing signal and the seventh timing signal in the valid phase are provided at the same time The signals respectively make the first timing switch, the seventh timing switch, and the fifth timing switch in the conducting state, and at the same time provide other timing signals in the invalid phase so that the other timing switches are in the closing state; the voltage output process is at the N+1th The timing period is the discharge process of the first pumping capacitor.

Preferably, the charging process of the first pumping capacitor is: when the second timing switch and the third timing switch are turned on, a power supply voltage is provided to the first end of the first pumping capacitor and the first pumping capacitor is The second end of the capacitor is grounded; the discharge process of the first pumping capacitor is: when the sixth timing switch and the seventh timing switch are turned on, the first end of the first pumping capacitor outputs a voltage to the outside, and at the same time provides A power supply voltage is sent to the second end of the first pumping capacitor to make the first end of the first pumping capacitor output a voltage; the charge recovery process of the first pumping capacitor is: in the first timing switch, When the ninth timing switch and the third timing switch are turned on, the voltage at the first end of the second pumping capacitor is recovered to the first end of the first pumping capacitor, and at the same time, the voltage of the first pumping capacitor is The second terminal is grounded to provide a power supply voltage to the second terminal of the second pumping capacitor; the charging process of the second pumping capacitor is to provide a power supply when the fourth timing switch and the fifth timing switch are turned on voltage to the first end of the second pumping capacitor while grounding the second end of the second pumping capacitor; the discharge process of the second pumping capacitor is: when the eighth timing switch and the ninth timing switch are in conduction When the first end of the second pumping capacitor outputs a voltage, at the same time, a power supply voltage is provided to the second end of the second pumping capacitor so that the first end of the second pumping capacitor outputs a voltage; The charge recovery process of the second pumping capacitor is: when the first timing switch, the seventh timing switch, and the fifth timing switch are turned on, the voltage at the first end of the first pumping capacitor is recovered to the first The first terminals of the two pumping capacitors are grounded at the second terminal of the second pumping capacitor to provide a power supply voltage to the second terminal of the first pumping capacitor.

The charge pump circuit of the present invention utilizes two charging and discharging units to output voltage alternately, which effectively reduces the ripple of the output voltage. In addition, the charge pump circuit of the present invention utilizes the mechanism of charge recovery, which effectively reduces the energy consumption of the circuit.

Description of drawings

FIG. 1 is a circuit diagram of a triple voltage charge pump in the prior art.

Fig. 2 is a circuit diagram of the present invention.

Fig. 3 is a circuit diagram of an embodiment of the present invention.

Fig. 4 is a timing diagram of the timing control embodiment of the present invention.

Detailed ways

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar extensions without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

In the following, specific embodiments of the present invention will be described in conjunction with the accompanying drawings. First, Fig. 2 is a circuit diagram of the present invention. A charge pump circuit includes two charging and discharging units U1 and U2 and a charge recovery sequential switch circuit, specifically including: a first pumping capacitor C1, a second pumping capacitor C2, and a power port Vcc, ground port GND, output port Vout, 9 sequential switches S1-S9.

In the circuit shown in Figure 2, the first timing switch S1 includes a control terminal, a first terminal and a second terminal, the control terminal receives the third timing signal CLK3, and the first terminal is electrically connected to the first pumping The first end of the capacitor C1, the second end is electrically connected to the first end of the second pumping capacitor C2; the second timing switch S2, which includes a control end, a first end and a second end, the control end Receive the first timing signal CLK1, the first end is electrically connected to the power port Vcc, the second end is electrically connected to the first end of the first pumping capacitor C1; the third timing switch S3 includes a control end , a first end and a second end, the control end receives the sixth timing signal CLK1b', the first end is electrically connected to the ground port GND, and the second end is electrically connected to the first pumping capacitor C1 The second terminal: the sixth timing switch S6, which includes a control terminal, a first terminal and a second terminal, the control terminal receives the second timing signal CLK2, the first terminal is electrically connected to the output port Vout, and the first terminal is electrically connected to the output port Vout. The two terminals are electrically connected to the first terminal of the first pumping capacitor C1; the seventh timing switch S7 includes a control terminal, a first terminal and a second terminal, the control terminal receives the fifth timing signal CLK2', the The first end is electrically connected to the power supply port Vcc, and the second end is electrically connected to the second end of the first pumping capacitor C1; the fourth timing switch S4 includes a control end, a first end and a second end, The control end receives the second timing signal CLK2, the first end is electrically connected to the power port Vcc, and the second end is electrically connected to the first end of the second pumping capacitor C2; the fifth timing switch S5, It includes a control terminal, a first terminal and a second terminal, the control terminal receives the seventh timing signal CLK2b', the first terminal is electrically connected to the ground port GND, and the second terminal is electrically connected to the second pump The second terminal of the sending capacitor C2; the eighth timing switch S8, which includes a control terminal, a first terminal and a second terminal, the control terminal receives the first timing signal CLK1, and the first terminal is electrically connected to the output port Vout , the second terminal is electrically connected to the first terminal of the second pumping capacitor C2; the ninth timing switch S9 includes a control terminal, a first terminal and a second terminal, and the control terminal receives the fourth timing signal CLK1 ', the first end is electrically connected to the power port Vcc, and the second end is electrically connected to the second end of the second pumping capacitor C2.

As shown in Figure 3 is an embodiment of the present invention, the timing switches S2, S4, S6, S7, S8, S9 are P-type metal oxide semiconductor (MetalOxideSemiconductor, MOS) transistors, and the timing switches S1, S3, S5 are N-type Metal oxide semiconductor (MetalOxideSemiconductor, MOS) transistor.

In this embodiment, the gate of S1 receives the timing signal CLK3, and the other two ends are respectively electrically connected to the first end of the first pumping capacitor C1 and the second end of the second pumping capacitor C2; the gate of S2 receives The drain and source of the timing signal CLK1 are respectively electrically connected to the power port Vcc and the first end of the first pumping capacitor C1; the gate of S3 receives the timing signal CLK1b', and the drain and source are respectively electrically connected to the ground Port GND and the second end of the first pumping capacitor C1; the gate of S6 receives the timing signal CLK2, and the drain and source are respectively electrically connected to the output port Vout and the first end of the first pumping capacitor C1; S7's The gate receives the timing signal CLK2', the drain and the source are respectively electrically connected to the second end of the first pumping capacitor C1 and the power port Vcc; the gate of S4 receives the timing signal CLK2, and the drain and the source are respectively electrically connected Connected to the power supply port Vcc and the first end of the second pumping capacitor C2; the gate of S5 receives the timing signal CLK2b', and the drain and source are electrically connected to the second end of the second pumping capacitor C2 and the ground port respectively GND; the gate of S8 receives the timing signal CLK1, and the drain and source are electrically connected to the output port Vout and the first end of the second pumping capacitor C2 respectively; the gate of S9 receives the timing signal CLK1', and the drain and source The poles are respectively electrically connected to the second terminal of the second pumping capacitor C2 and the power port Vcc.

FIG. 4 is a specific embodiment of timing control. As shown in the figure, the first timing signal CLK1 and the second timing signal CLK2 are the first group of two-phase non-overlapping timing signals; the fourth timing signal CLK1 'and the fifth timing signal CLK2' are the second group of two-phase non-overlapping timing signals; the sixth timing signal CLK1b' and the seventh timing signal CLK2b' are the third group of two-phase non-overlapping timing signals ; The third timing signal CLK3 is non-overlapping with the first group of two-phase non-overlapping timing signals. The falling edges of the second group of two-phase non-overlapping timing signals are respectively synchronized with the first group of two-phase non-overlapping timing signals, and the rising edges are respectively corresponding to the rising edges of the first group of two-phase non-overlapping timing signals. The edge is delayed for a certain time to include the effective phase of the third timing signal, and the delay time does not exceed the non-overlapping time of the first group of two-phase non-overlapping timing signals. The third group of two-phase non-overlapping timing signals are respectively inversion signals of the second group of two-phase non-overlapping timing signals.

When the timing control in FIG. 4 is applied to the circuit in FIG. 2 , the timing period of the third timing signal CLK3 is used as the timing period of the timing control. The charging and discharging process is as follows: in the Nth timing cycle, the first pumping capacitor C1 is used as a charging capacitor, and at the same time, the second pumping capacitor C2 is used as a discharging capacitor to output voltage, and in the N+1th timing cycle, the second The pumping capacitor C2 is used as a charging capacitor, and the first pumping capacitor C1 is used as a discharging capacitor to output an external voltage. When the first terminal of C1 or C2 is discharged, the power supply voltage Vcc is added to the second terminal of the discharging capacitor to make the The first end of the discharge capacitor gets the multiplied voltage. The charge recovery process is as follows: after C2 outputs to the outside in the Nth timing cycle, make the second end of C2 conduct with the power supply port, make the second end of C1 conduct with the ground port, and at the same time make C2 The first end of C1 is electrically connected to the first end of C1, so that the charge is transferred from the first end of C2 to the first end of C1 to obtain a recovery voltage; after C1 is output to the outside in the N+1th timing cycle, C1 The second end of C1 is connected to the power supply port, and the second end of C2 is connected to the ground port, and at the same time, the first end of C1 is electrically connected to the first end of C2, so that the charge is transferred from the first end of C1 One end is transferred to the first end of C2 to get recovery voltage. The voltage output process is: when C1 or C2 outputs to the outside, the recovery voltage and the multiplied voltage are superimposed and then output to the outside.

When the timing control shown in FIG. 4 is applied to the embodiment shown in FIG. 3 , the timing period of the third timing signal CLK3 is used as the timing period of the timing control. The timing control for this embodiment includes the following processes:

The charging and discharging process in the Nth timing cycle is as follows: before the end of the Nth timing cycle, CLK1, CLK1' and CLK1b' which are in the effective phase at the same time are provided to make S2, S3, S8, and S9 in the conduction state respectively, and at the same time provide Other timing signals of invalid phases keep other timing switches closed. When S2 and S3 are turned on, VCC is provided to the first end of C1 and the second end of C1 is grounded at the same time, C1 is charged at this time; when S8 and S9 are turned on, Vcc is provided to the second end of C2 at the first end of C2 Terminal generates a multiplied voltage, and at the same time, the first terminal of C2 is connected to Vout to output an external voltage, and C2 is discharged at this time.

The charge recovery process in the Nth timing cycle is: when CLK1 enters the inactive phase, provide CLK3 in the active phase, and at the same time provide CLK1' and CLK1b' in the active phase to make S1, S9, and S3 in the conduction state, and provide Other timing signals in inactive phases keep other timing switches off. When S3 and S9 are turned on, connect the second end of C1 to ground and provide Vcc to the second end of C2. When S1 is turned on, the first end of C1 and the first end of C2 are electrically connected. At this time, the second end of C2 The voltage at one terminal is recovered to the first terminal of C1.

The voltage output process is the discharge process of C2 in the Nth timing cycle, and the recovered voltage and the multiplied voltage are superimposed on the first terminal of C2 and then output to the outside.

The charging and discharging process in the N+1 timing cycle is as follows: at the beginning of the N+1 timing cycle, CLK2, CLK2' and CLK2b' which are in active phase at the same time are provided so that S6, S7, S4 and S5 are turned on respectively state, and at the same time provide other timing signals in invalid phases to make other timing switches in the closed state. When S4 and S5 are turned on, Vcc is provided to the first end of C2 and the second end of C2 is grounded at the same time, and C2 is charged at this time; when S6 and S7 are turned on, Vcc is provided to the second end of C1 at the first end of C2 terminal to generate a multiplied voltage, and at the same time, the first terminal of C1 is connected to Vout to output an external voltage, and C1 is discharged at this time.

The charge recovery process in the N+1 timing cycle is as follows: when CLK2 enters the invalid phase, CLK3 enters the effective phase again, and at the same time, CLK2' and CLK2b' in the effective phase are provided to make S1, S7, and S5 in the conduction state respectively, and at the same time Providing other timing signals in inactive phases causes other timing switches to be closed. When S5 and S7 are in conduction, connect the second end of C2 to the ground, provide Vcc to the second end of C1, and at the same time, S1 is in conduction, and electrically conduct the first end of C1 and the first end of C2. At this time, the voltage at the first end of C1 is recovered to the first end of C2.

The voltage output process is the discharge process of C1 in the N+1th time sequence cycle, and the recovered voltage and the multiplied voltage are superimposed on the first terminal of C1 and then output to the outside.

Combining FIG. 3 and FIG. 4 , the charge recovery mechanism of the charge pump circuit and the boosting mechanism of the charge pump can be obtained. The timing cycle of the timing signal CLK3 is defined as the timing cycle of this circuit, please refer to Figure 3 and Figure 4, in the Nth effective phase of CLK1 in the Nth timing cycle, S2, S3, S8, and S9 are all in the ON state , the first pumping capacitor C1 is in the charging state, the voltage at the first terminal is Vcc, and the voltage at the second terminal is 0; the second pumping capacitor C2 is in the discharging state, the output voltage at the first terminal is V _N , and the voltage at the second terminal is Vcc . Then enter the non-overlapping time of CLK1 and CLK2, S2, S4, S6, and S8 are all in the disconnected state, and the first end of the first pumping capacitor C1 and the second ground pumping capacitor C2 are in a floating state; at the same time, due to CLK1' and CLK1b' are still in effective phase, S3 and S9 continue to conduct, and the second terminals of the first pumping capacitor C1 and the second ground pumping capacitor C2 are respectively kept conductively connected to the ground port GND and the power port Vcc. Then in this state, CLK3 is in the effective phase Cn to turn on S1, and at this time, the charge will be guided from the first end of the second pumping capacitor C2 (high level node V _N ) to the first end of the first pumping capacitor C1 One end (low level node Vcc). If the switching loss is ignored, the voltage V _Cn at the first terminals of the two pumping capacitors after charge recovery can be obtained:

Before conduction: the charge amount of the second pumping capacitor C2 is C ₂ (V _N -Vcc), and the charge amount of C1 is C ₁ V _CC ;

After conduction: the sum of the charge of the first pumping capacitor C ₁ and the charge of the second pumping capacitor C ₂ is C ₁ V _Cn +C ₂ (V _Cn -Vcc);

Due to the conservation of charge before and after conduction, the following formula can be obtained:

C ₁ V _Cn +C ₂ (V _Cn -Vcc)＝C ₁ V _CC +C ₂ (V _N -Vcc)

push to get:

V _Cn ＝(C ₁ Vcc+C ₂ V _N )/(C ₁ +C ₂ )

Preferably, in one embodiment, two identical pumping capacitors are selected to form a triple voltage charge pump, that is, when the capacitance of the first pumping capacitor and the second pumping capacitor are the same, it can be obtained from the above formula:

V _Cn =(Vcc+V _N )/2(1)

After the charge recovery process is completed, after a period of non-overlapping time, the circuit enters the N+1th effective phase of CLK2 in the N+1th timing cycle, S4, S5, S6, and S7 are in the conduction state, and the first pumping Capacitor C1 is in a discharging state, and the second terminal of the first pumping capacitor C1 is connected to Vcc, then the output voltage of the first terminal of the first pumping capacitor C1 is recorded as V _N+1 , then:

V _N+1 ＝V _N +Vcc(2)

At the same time, C2 enters the charging phase, the upper plate is connected to Vcc, and the lower plate is connected to zero potential. The working process of the circuit is to repeat the above process. C1 and C2 alternately enter the charging and output phases, and perform charge recovery during the non-overlapping time of the timing signals, and guide the charge from the upper plate at a higher potential to the upper plate at a lower potential. plate. After the final circuit reaches a stable working state, there should be:

V _{N +} 1︱N _→∞ ＝V N︱N _→∞ (3)

Therefore, substituting formula (1)(2) into formula (3), we can get

V _Cn +Vcc＝V _N ＝(Vcc+V _N )/2+Vcc(4)

That is: V _N ＝3Vcc

According to the above analysis, it can be concluded that the final output voltage of the circuit is three times the power supply voltage, which realizes the function of the triple voltage charge pump circuit.

Preferably, another specific embodiment of the present invention is that the charge recovery timing switch S1 adopts a transmission gate, and other circuit structures and timing control are the same as the above embodiment.

In another specific embodiment of the present invention, the timing switch S2 and the timing switch S8 use the same timing switch; the timing switch S6 and the timing switch S4 use the same timing switch; the power port (Vcc), the The ground port (GND) and the output port (Vout) are respectively one; other circuit structures and timing control are the same as the above embodiments.

Above, the present invention has been exemplarily described in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner, as long as various improvements are adopted in the method concept and technical solutions of the present invention, or the present invention is implemented without improvement. The ideas and technical schemes directly applied to other occasions are within the protection scope of the present invention.

Claims (9)

1. A charge pump circuit, characterized in that, comprising: first pumping capacitor; a second pumping capacitor; Power port (Vcc); Ground port (GND); output port (Vout); Multiple timing switches; The power port and the output port are respectively connected in parallel to the first end of the first pumping capacitor through a timing switch, and the power port and the ground port are respectively connected in parallel to the first end of the first pumping capacitor through a timing switch. second end; The power supply port and the output port are respectively connected in parallel to the first end of the second pumping capacitor through a timing switch, and the power supply port and the ground port are respectively connected in parallel to the first end of the second pumping capacitor through a timing switch. second end; The first end of the first pumping capacitor is electrically connected in series with the first end of the second pumping capacitor through a timing switch, The timing switch includes: The first timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the first timing switch receives the third timing signal, and the first terminal of the first timing switch is electrically connected to the first the first end of the pumping capacitor, the second end of the first timing switch is electrically connected to the first end of the second pumping capacitor; The second timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the second timing switch receives the first timing signal, and the first terminal of the second timing switch is electrically connected to the power port , the second end of the second timing switch is electrically connected to the first end of the first pumping capacitor; The third timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the third timing switch receives the sixth timing signal, and the first terminal of the third timing switch is electrically connected to the ground port , the second end of the third timing switch is electrically connected to the second end of the first pumping capacitor; The fourth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the fourth timing switch receives the second timing signal, and the first terminal of the fourth timing switch is electrically connected to the power port , the second end of the fourth timing switch is electrically connected to the first end of the second pumping capacitor; The fifth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the fifth timing switch receives the seventh timing signal, and the first terminal of the fifth timing switch is electrically connected to the ground port , the second end of the fifth timing switch is electrically connected to the second end of the second pumping capacitor; The sixth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the sixth timing switch receives the second timing signal, and the first terminal of the sixth timing switch is electrically connected to the output port , the second end of the sixth timing switch is electrically connected to the first end of the first pumping capacitor; The seventh timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the seventh timing switch receives the fifth timing signal, and the first terminal of the seventh timing switch is electrically connected to the power port , the second terminal of the seventh timing switch is electrically connected to the second terminal of the first pumping capacitor; The eighth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the eighth timing switch receives the first timing signal, and the first terminal of the eighth timing switch is electrically connected to the output port , the second end of the eighth timing switch is electrically connected to the first end of the second pumping capacitor; The ninth timing switch includes a control terminal, a first terminal and a second terminal, the control terminal of the ninth timing switch receives the fourth timing signal, and the first terminal of the ninth timing switch is electrically connected to the power port , the second end of the ninth timing switch is electrically connected to the second end of the second pumping capacitor, The first timing signal and the second timing signal are a first group of two-phase non-overlapping timing signals; The fourth timing signal and the fifth timing signal are a second group of two-phase non-overlapping timing signals; The sixth timing signal and the seventh timing signal are a third group of two-phase non-overlapping timing signals; The third timing signal is non-overlapping with the first group of two-phase non-overlapping timing signals, The two falling edges of the second group of two-phase non-overlapping timing signals are respectively synchronized with the two falling edges of the first group of two-phase non-overlapping timing signals, and the two rising edges are respectively relative to the first group The two rising edges of the two-phase non-overlapping timing signals are delayed by a certain time to include the effective phase of the third timing signal, and the delay time is not longer than the first set of two-phase non-overlapping timing signals non-overlapping time. 2. The charge pump circuit according to claim 1, wherein the third group of two-phase non-overlapping timing signals are respectively inversion signals of the second group of two-phase non-overlapping timing signals. 3. The charge pump circuit according to any one of claims 1 to 2, wherein the first pumping capacitor is the same as the second pumping capacitor. 4. The charge pump circuit according to claim 3, characterized in that: the power port (Vcc), the ground port (GND) and the output port (Vout) are respectively one or more. 5. The charge pump circuit according to claim 4, characterized in that: the first timing switch is a single PMOS transistor or a single NMOS transistor or a transmission gate; the third timing switch and the fifth timing switch are N-type MOS transistors; the second timing switch, the fourth timing switch, the sixth timing switch, the seventh timing switch, the eighth timing switch and the ninth timing switch are P-type MOS transistors. 6. A timing control method for a charge pump circuit, used to control the charge pump circuit as claimed in claims 1-5, comprising the following process: In the charging and discharging process, the first pumping capacitor is used as the charging capacitor in the Nth timing cycle, and the second pumping capacitor is used as the discharging capacitor to output voltage externally, and the second pumping capacitor is used as the external output voltage in the N+1 timing cycle. The charging capacitor is used to make the first pumping capacitor output voltage as the discharge capacitor. When the first end of the discharge capacitor is discharged, the power supply voltage is added to the second end of the discharge capacitor to make the first end of the discharge capacitor Get the doubled voltage; In the charge recovery process, after the discharge capacitor of the Nth timing cycle is output to the outside and before the discharge capacitor of the N+1th timing cycle is output, the second terminal of the discharge capacitor of the Nth timing cycle is Conducting with the power supply port, making the second end of the charging capacitor of the Nth timing cycle and the ground port conductive, and simultaneously connecting the first end of the discharging capacitor of the Nth timing cycle with the The first end of the discharge capacitor in the N+1th timing cycle is electrically turned on, so that the charge is transferred from the first end of the discharge capacitor in the N+1th timing cycle to the discharge capacitor in the N+1th timing cycle. The first terminal obtains the recovery voltage; In the voltage output process, the recovered voltage is superimposed on the multiplied voltage and outputted by the discharge capacitor of the N+1th timing cycle; The charging and discharging process includes in the Nth timing cycle: the charging process of the first pumping capacitor and the discharging process of the second pumping capacitor, wherein the first timing that is simultaneously in the effective phase is provided before the end of the Nth timing cycle signal, the fourth timing signal, and the sixth timing signal make the second timing switch, the third timing switch, the eighth timing switch, and the ninth timing switch in the conduction state, and provide other timing signals in invalid phases to make other timing switches is closed; The charge recovery process is the charge recovery process of the first pumping capacitor in the Nth timing cycle, wherein when the first timing signal enters the inactive phase, the third timing signal in the active phase is provided, and at the same time, the active phase is provided. The fourth timing signal and the sixth timing signal of the phase respectively make the first timing switch, the ninth timing switch, and the third timing switch in the on state, and provide other timing signals in the invalid phase to make the other timing switches in the off state; The voltage output process is a discharge process of the second pumping capacitor in the Nth timing cycle; The charging and discharging process in the N+1th timing cycle includes: the discharging process of the first pumping capacitor and the charging process of the second pumping capacitor, wherein at the beginning of the N+1th timing cycle, the supply is simultaneously active The second timing signal, the fifth timing signal and the seventh timing signal of the phase respectively make the sixth timing switch, the seventh timing switch, the fourth timing switch and the fifth timing switch in the conduction state, and at the same time provide other timing switches in the invalid phase The signal makes other timing switches in the closed state; The charge recovery process is the charge recovery process of the second pumping capacitor in the N+1th timing period, wherein when the second timing signal enters the invalid phase, the third timing signal entering the valid phase is provided again, and at the same time Provide the fifth timing signal and the seventh timing signal in the effective phase to make the first timing switch, the seventh timing switch, and the fifth timing switch in the on state, and provide other timing signals in the invalid phase to make the other timing switches off state; The voltage output process is a discharge process of the first pumping capacitor in the N+1th timing period. 7. The timing control method of the charge pump circuit according to claim 6, wherein the charging process of the first pumping capacitor is carried out simultaneously with the discharging process of the second pumping capacitor; The discharging process of is carried out simultaneously with the charging and discharging process of the second pumping capacitor. 8. The timing control method of the charge pump circuit according to claim 6, wherein the charge recovery process is after the discharge process of the Nth timing cycle and in the discharge process of the N+1th timing cycle carried out before. 9. The timing control method of the charge pump circuit according to claim 6, wherein, The charging process of the first pumping capacitor is as follows: when the second timing switch and the third timing switch are turned on, a power supply voltage is provided to the first terminal of the first pumping capacitor, and at the same time, the first end of the first pumping capacitor is Two-terminal grounding; The discharge process of the first pumping capacitor is: when the sixth timing switch and the seventh timing switch are turned on, the first terminal of the first pumping capacitor outputs a voltage to the outside, and at the same time provides a power supply voltage to the first The second terminal of a pumping capacitor makes the first terminal output voltage; The charge recovery process of the first pumping capacitor is: when the first timing switch, the ninth timing switch and the third timing switch are turned on, the voltage at the first end of the second pumping capacitor is recovered to the first timing switch. a first end of a pumping capacitor, while grounding the second end of the first pumping capacitor to provide a power supply voltage to the second end of the second pumping capacitor; The charging process of the second pumping capacitor is as follows: when the fourth timing switch and the fifth timing switch are turned on, a power supply voltage is provided to the first terminal of the second pumping capacitor, and at the same time, the first terminal of the second pumping capacitor is Two-terminal grounding; The discharge process of the second pumping capacitor is as follows: when the eighth timing switch and the ninth timing switch are turned on, the first terminal of the second pumping capacitor outputs a voltage to the outside, and at the same time provides a power supply voltage to the first The second terminal of the second pumping capacitor makes the first terminal output voltage; The charge recovery process of the second pumping capacitor is: when the first timing switch, the seventh timing switch, and the fifth timing switch are turned on, the voltage at the first end of the first pumping capacitor is recovered to the first The first terminals of the two pumping capacitors are grounded at the second terminal of the second pumping capacitor to provide a power supply voltage to the second terminal of the first pumping capacitor.