Regulating circuit based on charge pump

Abstract

The invention provides an adjusting circuit based on a charge pump, and the circuit comprises a voltage dividing network which is connected with the output end of the charge pump, comprises a feedback node, and is used for carrying out the voltage dividing of the output voltage of the charge pump, so as to generate a feedback voltage; the first input end of the operational amplifier is used for receiving reference voltage; the second input end of the operational amplifier is connected with the feedback node and used for receiving feedback voltage; the output end of the operational amplifier is connected with the input end of the charge pump; the operational amplifier, the charge pump and the potential-divider network form a power supply loop; the feed-forward circuit is connected between the operational amplifier and the charge pump; the first feed-forward unit is connected between the output end and the input end of the charge pump so as to improve the response speed of the power supply loop. According to the scheme, the feedforward circuit adjusts the dominant pole of the power supply loop, and the output establishment speed of the charge pump is increased; the first feed-forward unit is connected with the output end and the input end of the charge pump, thereby improving the response speed and stability of the output of the charge pump.

Description

Technical Field

[0001] The disclosed embodiments of the present application relate to the technical field of power supply modulation, and more specifically, to a regulation circuit based on a charge pump. Background Art

[0002] Variable current driven high voltage charge pumps are widely used in memory chip systems, and the charge pumps are required to provide a stable voltage that can respond quickly to changes in load current.

[0003] In some power modulation technologies, the charge pump may respond slowly to current changes due to a large load capacitance at the output of the charge pump or a slow response speed at the input of the charge pump, which may lead to unstable output.

[0004] Therefore, how to improve the response speed and stability of the charge pump output becomes an urgent problem to be solved. Summary of the invention

[0005] According to an embodiment of the present application, the present invention proposes a regulation circuit based on a charge pump, which can improve the response speed and stability of the charge pump output.

[0006] According to one aspect of the present application, an exemplary charge pump-based regulation circuit is disclosed, including a voltage divider network, an operational amplifier, a feedforward circuit and a first feedforward unit; the voltage divider network is connected to the output end of the charge pump, wherein the voltage divider network includes a feedback node, and the voltage divider network is used to divide the output voltage of the charge pump to generate a feedback voltage; the first input end of the operational amplifier is used to receive a reference voltage; the second input end of the operational amplifier is connected to the feedback node for receiving the feedback voltage; the output end of the operational amplifier is used to connect to the input end of the charge pump; wherein the operational amplifier, the charge pump and the voltage divider network constitute a power supply loop; the feedforward circuit is connected between the operational amplifier and the charge pump to adjust the main pole of the power supply loop to the input end of the charge pump; the first feedforward unit is connected between the output end and the input end of the charge pump.

[0007] The above scheme adjusts the main pole of the power supply loop to the input end of the charge pump through the feedforward circuit so that the load capacitor of the charge pump can select a smaller capacitance value, reduce the capacitor volume, and prevent the main pole from changing due to the load change at the output end of the charge pump, thereby improving the output establishment speed of the charge pump; the output end and the input end of the charge pump are connected through the first feedforward unit, which improves the response speed of the input end of the charge pump, thereby improving the response speed of the power supply loop, that is, the charge pump can quickly adjust its output when the load changes, thereby improving the response speed and stability of the charge pump output. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present application will be further described below in conjunction with the accompanying drawings and implementation methods, in which:

[0009] Figure 1 It is a structural schematic diagram of an embodiment of a regulation circuit based on a charge pump of the present application;

[0010] Figure 2 is a structural schematic diagram of another embodiment of the regulation circuit based on the charge pump of the present application;

[0011] Figure 3 It is a structural schematic diagram of another embodiment of the regulation circuit based on the charge pump of the present application;

[0012] Figure 4 It is a structural schematic diagram of another embodiment of the regulation circuit based on the charge pump of the present application;

[0013] Figure 5 It is a structural schematic diagram of another embodiment of the regulation circuit based on the charge pump of the present application;

[0014] Figure 6 It is a structural schematic diagram of another embodiment of the regulation circuit based on the charge pump of the present application;

[0015] Figure 7 is a schematic structural diagram of an embodiment of a voltage divider network of the present application;

[0016] Figure 8 It is a structural diagram of an embodiment of a feedforward circuit of the present application. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution of the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0018] In some power supply circuits based on charge pumps, the output of the charge pump is usually sampled through a voltage divider network and then fed back to the operational amplifier at the front end of the charge pump. The operational amplifier outputs a control signal to control the output driving capability of the charge pump. Through the above-mentioned feedback loop, the output ripple and power consumption of the charge pump can be reduced to a certain extent according to the change of load current; however, in order to maintain a certain stability of the output of the charge pump, a load capacitor needs to be set at its output end, and the load capacitor needs to have a larger capacitance to improve the stability of the charge pump output. However, when the load capacitor is large, the settling speed of the charge pump output will be reduced.

[0019] The present application proposes a regulation circuit based on a charge pump, which can be applied to various NOR / NAND FLASH systems that require the use of high-voltage variable loads to improve the power supply loop response speed, reduce ripple, and improve the untimely change of the charge pump driving ability when the load current changes suddenly.

[0020] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of the structure of an embodiment of a charge pump-based regulation circuit of the present application; specifically, the charge pump-based regulation circuit 100 includes a voltage divider network 110, an operational amplifier 120, a feedforward circuit 130 and a first feedforward unit 140; the voltage divider network 110 is connected to the output end of the charge pump 150, wherein the voltage divider network 110 includes a feedback node 110a, and the voltage divider network 110 is used to divide the output voltage of the charge pump 150 to generate a feedback voltage; the first input end of the operational amplifier 120 is used to receive a reference voltage; ... The second input terminal of 120 is connected to the feedback node 110a for receiving the feedback voltage; the output terminal of the operational amplifier 120 is used to connect to the input terminal of the charge pump 150; wherein the operational amplifier 120, the charge pump 150 and the voltage divider network 110 constitute a power loop; the feedforward circuit 130 is connected between the operational amplifier 120 and the charge pump 150 to adjust the main pole of the power loop to the input terminal of the charge pump 150; the first feedforward unit 140 is connected between the output terminal and the input terminal of the charge pump 150 to improve the response speed of the power loop.

[0021] In the above scheme, the main pole of the power supply loop is adjusted to the input end of the charge pump 150 through the feedforward circuit 130, so that the load capacitor of the charge pump 150 can select a smaller capacitance, reduce the capacitor volume, and prevent the main pole from changing due to the load change at the output end OUT of the charge pump 150, thereby improving the output establishment speed of the charge pump 150; the output end and the input end of the charge pump 150 are connected through the first feedforward unit 140, which improves the response speed of the input end of the charge pump 150, thereby improving the response speed of the power supply loop, that is, the charge pump 150 can quickly adjust its output when the load changes, thereby improving the response speed and stability of the charge pump 150 output.

[0022] The specific structure of the charge pump 150 may adopt various existing charge pump structures. For example, the charge pump 150 may include a frequency modulation POSC module (not shown in the figure) and a PUMP-BODY module (not shown in the figure), which will not be described in detail in this application.

[0023] Please continue to refer to Figure 1After the main pole of the power loop is adjusted to the PBIAS node through the feedforward circuit 130, the response speed of the PBIAS node will be very slow, which will cause the output of the charge pump 150 to be unable to be adjusted in time when the load of the charge pump 150 changes rapidly. For example, its output voltage waveform may produce a large pit when the load current at the output end OUT switches from 0mA to 1mA, and the recovery time is long; therefore, the output end of the charge pump 150 is connected to the PBIAS node through the first feedforward unit 140, and the ripple jitter of the output voltage at the output end of the charge pump 150 is directly coupled to the PBIAS node, which can improve the response speed of the PBIAS node, and improve the response speed and stability of the charge pump 150 output.

[0024] Please refer to Figure 2 , Figure 2 1 is a schematic diagram of another embodiment of the charge pump-based regulation circuit of the present application; in some embodiments, the charge pump-based regulation circuit 100 further includes a second feedforward unit 160, which is connected between the output end of the charge pump 150 and the feedback node 110a. Connecting the output end of the charge pump 150 with the feedback node 110a of the voltage divider network 110 through the second feedforward unit 160 can improve the response speed of the feedback node 110a to the load change. For example, when the load current at the output end suddenly increases, the voltage at the output end OUT of the charge pump 150 decreases rapidly, and the second feedforward unit 160 and the first feedforward unit 140 can quickly pull down the voltage of the PBIAS node and the feedback node 110a. Compared with responding through the comparator and the voltage divider network 110, responding through the second feedforward unit 160 and the first feedforward unit 140 improves the response speed of the PBIAS node and the feedback node 110a.

[0025] Please continue to refer to Figure 2 , Figure 2 1 shows a connection mode of the load capacitor CL. The load capacitor CL may be connected between the output terminal OUT of the charge pump 150 and the ground.

[0026] It should be noted that, in the present application, those skilled in the art should be aware that "ground" does not necessarily mean actual "grounding", and the "ground" can be a low potential point or a "reference ground voltage point", which can be shared in the circuit.

[0027] Please refer to Figure 3 , Figure 3It is a structural diagram of another embodiment of the regulation circuit based on the charge pump of the present application; in some embodiments, the first feedforward unit 140 may include a first capacitive element, which is connected between the output end and the input end of the charge pump 150; the second feedforward unit 160 may include a second capacitive element, which is connected between the output end of the charge pump 150 and the feedback node 110a; the first capacitive element may be a capacitor C1, and the second capacitive element may be a capacitor C2; the feedback node 110a and the PBIAS node are coupled to the output end OUT of the charge pump 150 through a capacitor, and zero-pole compensation is performed on the feedback node 110a and the PBIAS node, and the ripple jitter in the output voltage of the charge pump 150 can be directly coupled to the above two nodes through the capacitor, thereby improving the response speed of the above two nodes.

[0028] It should be noted that Figure 3 The capacitor C1 and the capacitor C2 are only one embodiment of the first feedforward unit 140 and the second feedforward unit 160. In other embodiments, they are not limited to the above connection methods or elements.

[0029] Please refer to Figure 4 , Figure 4 It is a structural diagram of another embodiment of the regulation circuit based on the charge pump of the present application; the regulation circuit may also include a current compensation unit 170, which is connected to the output end of the charge pump 150; the current compensation unit 170 is used to increase the compensation current when the load current at the output end of the charge pump decreases; and, when the load current at the output end of the charge pump increases, reduce the compensation current.

[0030] In the above scheme, the compensation current generated by the current compensation unit 170 when the load current changes, when the output voltage of the charge pump is high or the driving capability is strong, the excess charge is discharged through the current compensation unit 170 to maintain the stability of the output terminal OUT, which can reduce the pit of the output voltage waveform of the charge pump 150 and accelerate the response of the power supply loop.

[0031] In some embodiments, the current compensation unit 170 may include a current source and a controllable switch path, the current source is used to generate a compensation current in the current compensation unit 170; the control end of the controllable switch path is connected to the output end of the operational amplifier 120, and the controllable switch path controls the magnitude of the compensation current in the current compensation unit 170 based on the output signal of the operational amplifier 120.

[0032] Specifically, when the load current of the charge pump 150 suddenly increases, the output signal of the operational amplifier 120 promptly controls the duty cycle of the controllable switch path to decrease or controls the controllable switch path to be directly disconnected; when the load current of the charge pump 150 suddenly decreases, the output signal of the operational amplifier 120 can promptly control the duty cycle of the controllable switch path to increase or keep it turned on.

[0033] The output signal of the operational amplifier 120 can be a digital signal, which can control the controllable switch path to continuously switch between on and off, and control the current size of the controllable switch path by controlling the duty cycle of the controllable switch path; the current source can be a controllable current source or an uncontrollable current source, which is selected according to the specific circuit; the current size flowing through the current compensation unit 170 is jointly determined by the duty cycle of the controllable switch path and the maximum current provided by the current source.

[0034] Please refer to Figure 5 , Figure 5 It is a structural schematic diagram of another embodiment of the regulation circuit based on the charge pump of the present application; Figure 5 One specific implementation of the current compensation unit 170 is shown. Specifically, the current source can be a controllable current source gv1, and the first end of the controllable current source gv1 is connected to the output end of the charge pump 150; the controllable switch path (not shown in the figure) can include a controllable switch element Q1, the control end of the controllable switch element Q1 is connected to the output end of the operational amplifier 120, the first end of the controllable switch element Q1 is connected to the second end of the controllable current source, and the second end of the controllable switch element Q1 is grounded.

[0035] In the present embodiment, the controllable current source gv1 can control the maximum current of the current compensation unit 170, and the control end of the controllable switch element Q1 receives the output signal EN of the operational amplifier 120. Therefore, the conduction capability of the current compensation unit 170 can be controlled based on the output signal EN of the operational amplifier 120; for example, when the output load current of the charge pump 150 is small or close to zero, since the current of the current compensation unit 170 is equivalent to a part of the load current, the voltage of the PBIAS node can be appropriately reduced; when the output load current of the charge pump 150 suddenly increases, the output signal EN of the operational amplifier 120 controls the duty cycle of the controllable switch element Q1 to decrease or directly controls the controllable switch element Q1 to be continuously closed, thereby reducing the pit generated by the output voltage waveform of the charge pump 150 and improving the response speed of the power supply loop.

[0036] It should be noted that Figure 5 The above embodiment is only an illustrative description of an embodiment of the current compensation unit 170. Those skilled in the art may make adaptive changes based on the inventive concept of the present application, such as adjusting the number of controllable switching elements Q1, etc., to achieve the same or similar effects, which are all improvements of the present application and do not exceed the protection scope of the present application.

[0037] Please refer to Figure 6 , Figure 6 is a structural diagram of another embodiment of the regulation circuit based on the charge pump of the present application; specifically, Figure 6A second specific implementation of the current compensation unit 170 is shown, the current source may be a stable current source (not shown in the figure); the controllable switch path may include a current mirror path 171 and a first controllable switch path 172, the current mirror path 171 includes a reference current path 1711 and a mirror current path 1712, the first end of the reference current path 1711 is connected to the stable current source to receive the reference current Iref, and the second end of the reference current path 1711 is grounded; the control end of the mirror current path 1712 is connected to the control end of the reference current path 1711, the control ends of the mirror current path 1712 and the reference current path 1711 are connected to the stable current source, and the second end of the mirror current path 1712 is grounded; the control end of the first controllable switch path 172 is connected to the output end of the operational amplifier 120, the first end of the first controllable switch path 172 is connected to the output end of the charge pump 150, and the second end of the first controllable switch path 172 is connected to the first end of the mirror current path 1712.

[0038] In the present embodiment, the stable current source provides a reference current Iref for the reference current path 1711, the mirror current path 1712 generates a mirror current based on the reference current Iref and the output voltage of the charge pump 150, and the control end of the first controllable switch path 172 is connected to the output signal EN of the operational amplifier 120, so that the operational amplifier 120 can control the duty cycle of the first controllable switch path 172, and thus control the current size of the current compensation unit 170; for example, when the output load current of the charge pump 150 is small or nearly zero, since the current of the current compensation unit 170 is equivalent to a part of the load current, the voltage of the PBIAS node can be appropriately reduced; when the output load current of the charge pump 150 suddenly increases, the operational amplifier 120 outputs the signal EN to control the duty cycle of the first controllable switch path 172 to decrease or directly controls the first controllable switch path 172 to be continuously closed, thereby reducing the pit generated by the output voltage waveform of the charge pump 150 and improving the response speed of the power supply loop.

[0039] It should be noted that in Figure 6 In the illustrated embodiment, the mirror current path 1712 and the first controllable switch path 172 are each composed of three controllable switch elements, while in other embodiments, the mirror current path 1712 and the first controllable switch path 172 may also select any other number of controllable switch elements, and the technical effect of the present application may also be achieved; in addition, the controllable switch elements used in the reference current path 1711, the mirror current path 1712 and the first controllable switch path 172 may be transistors, MOSFETs, IGBTs, etc., which are not limited in the present application.

[0040] Please continue to refer to Figure 6In some embodiments, the controllable switch path may further include a second controllable switch path 173, the control end of the second controllable switch path 173 is used to receive a configuration signal, and the configuration signal is used to control the duty cycle of the second controllable switch path 173; the second controllable switch path 173 is connected in series between the first controllable switch path 172 and the mirror current path 1712, the first end of the second controllable switch path 173 is connected to the second end of the first controllable switch path 172, and the second end of the second controllable switch path 173 is connected to the first end of the mirror current path 1712.

[0041] In the above solution, the second controllable switch path 173 adjusts the duty cycle based on the configuration signal, so as to adjust the maximum on-current of the current compensation unit 170 .

[0042] In other embodiments, the current compensation unit 170 may also be implemented by a resistor string structure, and the present application does not limit the specific structure of the current compensation unit 170 .

[0043] Please refer to Figure 7 , Figure 7 It is a structural diagram of an embodiment of a voltage divider network of the present application; the voltage divider network 110 may include a first resistor R1 and a second resistor R2, one end of the first resistor R1 is connected to the output terminal OUT of the charge pump 150, and the other end is connected to the second resistor R2, one end of the second resistor R2 is grounded, and the common end of the first resistor R1 and the second resistor R2 is connected to the operational amplifier 120 as a feedback node 110a; of course, the voltage divider network 110 can also adopt an active device structure such as MOSFET, which is not limited in the present application.

[0044] Please refer to Figure 8 , Figure 8 It is a structural diagram of an embodiment of the feedforward circuit of the present application; the feedforward circuit 130 may include a resistor R3 and a third capacitive element C3, one end of the resistor R3 is connected to the output end of the operational amplifier, and the other end is connected to the PBIAS node; one end of the third capacitive element C3 is connected to the PBIAS node, and the other end is grounded; the main pole of the power supply loop is adjusted to the PBIAS node located at the input end of the charge pump 150 through the feedforward circuit 130, so that the load capacitor CL of the charge pump 150 can select a smaller capacitance, reduce the capacitor volume, and prevent the main pole from changing due to the load change of the output end OUT of the charge pump 150, thereby improving the output establishment speed of the charge pump 150.

[0045] It is easy for a person skilled in the art to know that many modifications and changes can be made to the device and method while maintaining the teaching content of the present application. Therefore, the above disclosure should be considered as limited only by the scope of the appended claims.

Claims

1. A regulation circuit based on a charge pump, characterized in that: include: A voltage divider network connected to the output end of the charge pump, wherein the voltage divider network includes a feedback node, and the voltage divider network is used to divide the output voltage of the charge pump to generate a feedback voltage; An operational amplifier, wherein a first input terminal of the operational amplifier is used to receive a reference voltage; a second input terminal of the operational amplifier is connected to the feedback node and is used to receive the feedback voltage; an output terminal of the operational amplifier is used to connect to an input terminal of the charge pump; wherein the operational amplifier, the charge pump and the voltage divider network form a power supply loop; a feed-forward circuit connected between the operational amplifier and the charge pump to adjust the main pole of the power supply loop to the input terminal of the charge pump; The first feedforward unit is connected between the output terminal and the input terminal of the charge pump.

2. The regulating circuit according to claim 1, characterized in that: Further including: The second feedforward unit is connected between the output terminal of the charge pump and the feedback node.

3. The regulating circuit according to claim 2, characterized in that: The first feedforward unit comprises a first capacitive element connected between an output terminal and an input terminal of the charge pump; The second feedforward unit includes a second capacitive element connected between the output terminal of the charge pump and the feedback node.

4. The regulating circuit according to claim 1, characterized in that: Also includes: A current compensation unit connected to the output end of the charge pump; The current compensation unit is used to increase the compensation current when the load current at the output end of the charge pump decreases; And, when the load current at the output end of the charge pump increases, the compensation current is reduced.

5. The regulating circuit according to claim 4, characterized in that: The current compensation unit comprises: a current source, used to generate a compensation current in the current compensation unit; A controllable switch path, wherein a control end of the controllable switch path is connected to an output end of the operational amplifier, and the controllable switch path controls the magnitude of the compensation current in the current compensation unit based on an output signal of the operational amplifier.

6. The regulating circuit according to claim 5, characterized in that: The current source is a controllable current source, and a first end of the controllable current source is connected to an output end of the charge pump; The controllable switch path includes a controllable switch element, a control end of the controllable switch element is connected to the output end of the operational amplifier, a first end of the controllable switch element is connected to the second end of the controllable current source, and a second end of the controllable switch element is grounded.

7. The regulating circuit according to claim 5, characterized in that: The current source is a stable current source; The controllable switch path includes a current mirror path and a first controllable switch path, the current mirror path includes a reference current path and a mirror current path, a first end of the reference current path is connected to the stable current source to receive a reference current, and a second end of the reference current path is grounded; The control end of the mirror current path is connected to the control end of the reference current path, the control ends of the mirror current path and the reference current path are connected to the stable current source, and the second end of the mirror current path is grounded; the control end of the first controllable switch path is connected to the output end of the operational amplifier, the first end of the first controllable switch path is connected to the output end of the charge pump, and the second end of the first controllable switch path is connected to the first end of the mirror current path.

8. The regulating circuit according to claim 7, characterized in that: The controllable switch path also includes a second controllable switch path, a control end of the second controllable switch path is used to receive a configuration signal, and the configuration signal is used to control the duty cycle of the second controllable switch path; the second controllable switch path is connected in series between the first controllable switch path and the mirror current path, the first end of the second controllable switch path is connected to the second end of the first controllable switch path, and the second end of the second controllable switch path is connected to the first end of the mirror current path.

9. The regulating circuit according to claim 1, characterized in that: The feedforward circuit comprises: A resistor, wherein the output end of the operational amplifier is connected to the input end of the charge pump through the resistor.

10. The regulating circuit according to claim 9, characterized in that: The feedforward circuit further comprises: A third capacitive element, the input end of the charge pump is grounded through the third capacitive element.

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