Charge pump circuit with current control type fixed voltage output and charge pump system

Abstract

The invention discloses a current control type charge pump circuit with fixed voltage output and a charge pump system, and relates to the technical field of charge pumps. The circuit comprises a charge pump module which is used for charging a floating capacitor in the charge pump module by using a preset voltage source and an adjustable charge pump current source module in a charging time sequence and discharging the floating capacitor in a discharging time sequence to obtain an output voltage of the charge pump module; the error signal generation module is used for obtaining an error voltage signal according to the input voltage and the output voltage of the charge pump module; the current signal generation module is used for compensating a current signal for controlling the adjustable charge pump current source module according to the error voltage signal to obtain a compensated current signal; and the adjustable charge pump current source module is used for controlling the charging current intensity when the charge pump module charges the floating capacitor under the control of the current signal so as to realize fixed voltage output.

Description

Technical Field

[0001] The present invention relates to the technical field of charge pumps, and in particular, to a charge pump circuit and a charge pump system with a current-controlled fixed voltage output. Background Art

[0002] A charge pump circuit is a circuit that generates a higher or lower output voltage from an input voltage and is often applied to power stage analog integrated circuits. However, in the related art charge pump circuits, if a stable charge pump output voltage is desired, a voltage multiplier or N - times voltage multiplier circuit is often used, and then the required output voltage is obtained through an LDO circuit. This solution requires two conversions to obtain the required voltage, resulting in excessive consumption during the conversion process and a decrease in efficiency. Especially when the input voltage is high enough, further step - down through an LDO causes a significant increase in heat generation. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, the first object of the present invention is to propose a charge pump circuit with a current-controlled fixed voltage output to improve efficiency and reduce heat generation.

[0004] The second object of the present invention is to propose a charge pump system.

[0005] To achieve the above object, an embodiment of the first aspect of the present invention proposes a charge pump circuit with a current-controlled fixed voltage output. The circuit includes: a charge pump module, the first end of the charge pump module is connected to a preset voltage source, the second end of the charge pump module is connected to an adjustable charge pump current source module. The charge pump module is used to charge a floating capacitor in the charge pump module using the preset voltage source and the adjustable charge pump current source module during the charging timing, discharge the floating capacitor during the discharging timing, and use the discharge voltage of the floating capacitor as the output voltage of the charge pump module; an error signal generation module, connected to the charge pump module, the error signal generation module is used to obtain an error voltage signal based on the input voltage and the output voltage of the charge pump module; a current signal generation module, connected to the error signal generation module, the current signal generation module is used to obtain a current signal based on the error voltage signal, where the current signal is a signal for controlling the adjustable charge pump current source module; the adjustable charge pump current source module, connected to the charge pump module and the current signal generation module, the adjustable charge pump current source module is used to control the charging current intensity when the charge pump module charges the floating capacitor under the control of the current signal to achieve a fixed voltage output.

[0006] In addition, the charge pump circuit with a current-controlled fixed voltage output according to the embodiment of the present invention may further have the following additional technical features: In an embodiment of the present invention, the charge pump module includes a first floating capacitor. The charge pump module further includes: a first charging switch, the first end of the first charging switch is connected to the first end of the first floating capacitor; a second charging switch, the first end of the second charging switch is connected to the second end of the first floating capacitor, and the second end of the second charging switch is adapted to be connected to the adjustable charge pump current source module; a first discharging switch, the first end of the first discharging switch is connected to the second end of the first floating capacitor; a second discharging switch, the first end of the second discharging switch is connected to the first end of the first floating capacitor, and the second end of the second discharging switch is adapted to be connected to the output end of the charge pump module; wherein, the second end of the first charging switch and the second end of the first discharging switch are connected and adapted to be connected to the preset voltage source, the first charging switch and the second charging switch are used to be closed in the charging timing, so as to charge the first floating capacitor by using the preset voltage source under the control of the adjustable charge pump current source module, and the first discharging switch and the second discharging switch are used to be closed in the discharging timing, so as to discharge the first floating capacitor.

[0007] In an embodiment of the present invention, the adjustable charge pump current source module includes: a current control tube, the first end of the current control tube is adapted to be connected to the charge pump module, and the control end of the current control tube is adapted to be connected to the current signal generating module; a current sampling resistor, the first end of the current sampling resistor is connected to the second end of the current control tube, and the second end of the current sampling resistor is grounded; wherein, the current control tube is used to adjust the current intensity flowing through itself according to the current signal and the sampling current, so as to control the charging current intensity when charging the floating capacitor, and the sampling current is the current flowing through the current sampling resistor.

[0008] In an embodiment of the present invention, the error signal generating module includes: a reference voltage source, used to output a reference voltage; a first sub-module, the input end of the first sub-module is adapted to be connected to the charge pump module; a second sub-module, the first input end of the second sub-module is connected to the output end of the first sub-module, the second input end of the second sub-module is connected to the reference voltage source, and the output end of the second sub-module is adapted to be connected to the output end of the error signal generating module; wherein, the first sub-module is used to obtain the input voltage and the output voltage, and obtain the voltage change amount according to the input voltage and the output voltage, and the second sub-module is used to obtain the error voltage signal according to the voltage change amount and the reference voltage.

[0009] In one embodiment of the present invention, the first input end of the current signal generation module is connected to the output end of the second sub-module, and the second input end of the current signal generation module is connected to a current holding voltage source; wherein, the current signal generation module is configured to convert the error voltage signal into a current signal according to the current holding voltage output by the current holding voltage source, and control the adjustable charge pump current source module according to the current signal.

[0010] In one embodiment of the present invention, the charge pump module includes at least one floating capacitor; wherein, when the charge pump module includes two floating capacitors, the charge pump module includes a second floating capacitor and a third floating capacitor, and the charge pump module further includes: a third discharge switch, the first end of the third discharge switch is connected to the first end of the second floating capacitor; a fourth discharge switch, the first end of the fourth discharge switch is connected to the second end of the second floating capacitor, and the second end of the fourth discharge switch is connected to the first end of the third floating capacitor; a fifth discharge switch, the first end of the fifth discharge switch is connected to the second end of the third floating capacitor, and the second end of the fifth discharge switch is adapted to be connected to the output end of the charge pump module; a third charging switch, the first end of the third charging switch is connected to the first end of the second floating capacitor; a fourth charging switch, the first end of the fourth charging switch is connected to the second end of the second floating capacitor; a fifth charging switch, the first end of the fifth charging switch is connected to the second end of the fourth discharge switch; a sixth charging switch, the first end of the sixth charging switch is connected to the second end of the third floating capacitor, and the second end of the sixth charging switch is connected to the second end of the fourth charging switch; wherein, the second end of the third discharge switch and the second end of the fourth charging switch are connected and adapted to be connected to the preset voltage source, the second end of the third charging switch and the second end of the fifth charging switch are connected and adapted to be connected to the adjustable charge pump current source module, the third discharge switch, the fourth discharge switch and the fifth discharge switch are used to close during the discharge timing to discharge the second floating capacitor and the third floating capacitor, and the third charging switch, the fourth charging switch, the fifth charging switch and the sixth charging switch are used to close during the charging timing to charge the second floating capacitor and the third floating capacitor by using the preset voltage source under the control of the adjustable charge pump current source.

[0011] In one embodiment of the present invention, the charge pump module further includes: a first capacitor, the first end of the first capacitor is connected to the second end of the sixth charging switch and adapted to be connected to the preset voltage source, and the second end of the first capacitor is connected to the second end of the fifth discharge switch and adapted to be connected to the output end of the charge pump module.

[0012] In an embodiment of the present invention, the first sub-module is specifically configured to obtain the voltage change amount according to the following formula: V1 = k (VCP - PVDD), where V1 is the voltage change amount, k is a preset coefficient, VCP is the output voltage, and PVDD is the input voltage.

[0013] In an embodiment of the present invention, the current sampling resistor is the on-resistance of a MOS transistor. The first end of the MOS transistor is connected to the second end of the current control transistor, the second end of the MOS transistor is grounded, and the control end of the MOS transistor is connected to the output end of the current holding voltage source.

[0014] To achieve the above object, an embodiment of the second aspect of the present invention provides a charge pump system, including the above-mentioned charge pump circuit with current-controlled fixed voltage output.

[0015] According to the charge pump circuit and the charge pump system with current-controlled fixed voltage output of the embodiments of the present invention, the circuit includes: a charge pump module, the power supply terminal of the charge pump module is connected to a preset voltage source. The charge pump module is configured to charge the floating capacitor in the charge pump module using the preset voltage source during the charging timing, discharge the floating capacitor during the discharging timing, and use the discharge voltage of the floating capacitor as the output voltage of the charge pump module; an error signal generation module, the first input terminal of the error signal generation module is connected to the output terminal of the charge pump module, the second input terminal of the error signal generation module is connected to the power supply terminal of the charge pump module. The error signal generation module is configured to obtain the input voltage and the output voltage of the charge pump module, and obtain an error voltage signal based on the output voltage and the input voltage; a current signal generation module, the input terminal of the current signal generation module is connected to the output terminal of the error signal generation module. The current signal generation module is configured to compensate the current signal according to the error voltage signal to obtain a compensated current signal; an adjustable charge pump current source module, the output terminal of the adjustable charge pump current source module is connected to the control terminal of the charge pump module, and the control terminal of the adjustable charge pump current source module is connected to the output terminal of the current signal generation module. The adjustable charge pump current source module is configured to control the charging current intensity when the charge pump module charges the floating capacitor under the control of the current signal to achieve a fixed voltage output. Thus, by setting the error signal generation module, the current signal generation module, and the adjustable charge pump current source module, a stable output voltage can be obtained only by performing a single transformation on the input voltage, with high efficiency and low heat generation.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0017] Figure 1It is a structural block diagram of a current-controlled fixed-voltage-output charge pump circuit according to an embodiment of the present invention; Figure 2 It is a circuit diagram of a current-controlled fixed-voltage-output charge pump circuit according to a specific embodiment of the present invention; Figure 3 It is a circuit diagram of a current-controlled fixed-voltage-output charge pump circuit according to another specific embodiment of the present invention; Figure 4 It is a structural block diagram of a charge pump system according to an embodiment of the present invention. Detailed implementation manners

[0018] Next, the current-controlled fixed-voltage-output charge pump circuit and charge pump system according to the embodiments of the present invention will be described with reference to the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described with reference to the accompanying drawings are exemplary and should not be construed as limiting the present invention.

[0019] Figure 1 It is a structural block diagram of a current-controlled fixed-voltage-output charge pump circuit according to an embodiment of the present invention.

[0020] As Figure 1 shown, the current-controlled fixed-voltage-output charge pump circuit 100 includes: a charge pump module 101, the first end of the charge pump module 101 is connected to a preset voltage source, the second end of the charge pump module 101 is connected to an adjustable charge pump current source module 104, and the charge pump module 101 is configured to charge the floating capacitor in the charge pump module 101 using the preset voltage source and the adjustable charge pump current source module 104 during the charging timing, discharge the floating capacitor during the discharging timing, and use the discharging voltage of the floating capacitor as the output voltage of the charge pump module 101; an error signal generation module 102, the error signal generation module 102 is connected to the charge pump module 101, and the error signal generation module 102 is configured to obtain the input voltage and output voltage of the charge pump module 101 and obtain an error voltage signal based on the input voltage and the output voltage; a current signal generation module 103, the current signal generation module 103 is connected to the error signal generation module 102, and the current signal generation module 103 is configured to obtain a current signal based on the error voltage signal, where the current signal is a signal for controlling the adjustable charge pump current source module 104; an adjustable charge pump current source module 104, the adjustable charge pump current source module 104 is connected to the charge pump module 101 and the current signal generation module 103, and the adjustable charge pump current source module 104 is configured to control the charging current intensity when the charge pump module 101 charges the floating capacitor under the control of the current signal to achieve a fixed voltage output.

[0021] Specifically, the charge pump circuit 100 with current-controlled fixed-voltage output includes four modules: a charge pump module 101, an error signal generation module 102, a current signal generation module 103, and an adjustable charge pump current source module 104. The charge pump module 101 is the main module of the charge pump circuit 100 with current-controlled fixed-voltage output. The power supply terminal of the charge pump module 101 is the input terminal of the charge pump circuit 100 with current-controlled fixed-voltage output, and the output terminal of the charge pump module 101 is the output terminal of the charge pump circuit 100 with current-controlled fixed-voltage output. The output voltage of the above-mentioned preset voltage source is the input voltage of the charge pump module 101, and also the input voltage of the charge pump circuit 100 with current-controlled fixed-voltage output. The output voltage of the charge pump module 101 is the voltage output by the charge pump module 101, and also the output voltage of the charge pump circuit 100 with current-controlled fixed-voltage output.

[0022] Among them, the charge pump module 101 internally includes floating capacitors, and the working timing of setting the floating capacitors includes a charging timing and a discharging timing. During the charging timing, the charge pump module 101 charges the floating capacitors using the input voltage. During the discharging timing, the charge pump module 101 discharges the floating capacitors, thereby obtaining the output voltage of the charge pump module 101.

[0023] By setting appropriate charging timing duration and discharging timing duration, the output voltage of the charge pump module 101 can be made to be the target voltage.

[0024] However, since the output voltage of the charge pump module 101 may fluctuate, in order to enable the charge pump module 101 to achieve fixed-voltage output, the error signal generation module 102, the current signal generation module 103, and the adjustable charge pump current source module 104 are provided.

[0025] The error signal generation module 102, the current signal generation module 103, and the adjustable charge pump current source module 104 are modules for compensating the charge pump module 101. The error signal generation module 102 needs to obtain the output voltage and input voltage of the charge pump module 101, obtain the fluctuation situation of the output voltage of the charge pump module 101 based on the output voltage and input voltage, and control the adjustable charge pump current source module 104 to control the charge pump module 101 to charge the floating capacitors according to the fluctuation situation of the output voltage to achieve fixed-voltage output. For example, when the output voltage decreases, the charging ability of the charge pump module 101 for the floating capacitors during the charging timing can be increased. When the output voltage increases, the charging ability of the charge pump module 101 for the floating capacitors during the charging timing can be decreased, thereby making the output voltage of the charge pump module 101 fixed at the target voltage and avoiding fluctuations in the output voltage of the charge pump module 101.

[0026] Since the current signal generation module 103 is used to control the adjustable charge pump current source module 104 by using the current signal output by itself, and then control the charge pump module 101 to charge the floating capacitor based on the adjustable charge pump current source module 104, it is necessary to determine the fluctuation of the output voltage according to the difference between the input voltage and the output voltage and perform compensation. Specifically, the error signal generation module 102 generates an error voltage signal according to the input voltage and the output voltage, and the current signal generation module 103 obtains a current signal according to the error voltage signal. This current signal is a newly generated current signal. The new current signal that can meet the requirements is used to replace the original current signal that cannot meet the requirements, so as to realize current signal compensation. That is to say, when the output voltage decreases and is less than the target voltage, a current signal is generated to improve the charging ability of the charge pump module 101 for the floating capacitor in the charging timing. When the output voltage increases and is greater than the target voltage, a current signal is generated to reduce the charging ability of the charge pump module 101 for the floating capacitor in the charging timing. Thus, the output voltage can be fixed at the target voltage to achieve a fixed voltage output.

[0027] Therefore, by setting the error signal generation module 102, the current signal generation module 103, and the adjustable charge pump current source module 104, a stable output voltage can be obtained only by performing a single transformation on the input voltage, with high efficiency and low heat generation.

[0028] In some embodiments of the present invention, the charge pump module 101 includes a first floating capacitor. The charge pump module 101 further includes: a first floating capacitor; a first charging switch, the first end of the first charging switch is connected to the first end of the first floating capacitor; a second charging switch, the first end of the second charging switch is connected to the second end of the first floating capacitor, and the second end of the second charging switch is adapted to be connected to the adjustable charge pump current source module 104; a first discharge switch, the first end of the first discharge switch is connected to the second end of the first floating capacitor; a second discharge switch, the first end of the second discharge switch is connected to the first end of the first floating capacitor, and the second end of the second discharge switch is adapted to be connected to the output end of the charge pump module 101; wherein, the second end of the first charging switch and the second end of the first discharge switch are connected and adapted to be connected to a preset voltage source. The first charging switch and the second charging switch are used to be closed in the charging timing to charge the first floating capacitor by using the preset voltage source under the control of the adjustable charge pump current source module 104. The current control tube is used to control the current intensity of the charging current for charging the first floating capacitor. The first discharge switch and the second discharge switch are used to be closed in the discharging timing to discharge the first floating capacitor.

[0029] The adjustable charge pump current source module 104 includes: a current control transistor, the first end of the current control transistor is adapted to be connected to the charge pump module 101, and the control end of the current control transistor is adapted to be connected to the current signal generation module 103; a current sampling resistor, the first end of the current sampling resistor is connected to the second end of the current control transistor, and the second end of the current sampling resistor is grounded; wherein, the current control transistor is used to adjust the current intensity flowing through itself according to the current signal and the sampled current, so as to control the charging current intensity when charging the floating capacitor, and the sampled current is the current flowing through the current sampling resistor. For example, the current signal output by the current signal generation module 103 can control the conduction degree of the current control transistor in the charging timing, so as to control the current intensity of the charging current for charging the first floating capacitor. For another example, the current signal output by the current signal generation module 103 can control the conduction current magnitude of the current control transistor in the charging timing, so as to control the current intensity of the charging current for charging the first floating capacitor.

[0030] The current sampling resistor is used to enable the adjustable charge pump current source module 104 to obtain the current intensity of the sampled current flowing through the current sampling resistor through the sampling resistor terminal, and control the charge pump module 101 to charge the floating capacitor according to the current intensity of the sampled current flowing through the current sampling resistor. For example, the voltage at the first end of the current sampling resistor can be obtained, and the current flowing through the current sampling resistor can be obtained according to the voltage at the first end of the current sampling resistor and the resistance value of the current sampling resistor, so as to obtain the current intensity of the sampled current.

[0031] The sampling resistor terminal of the above adjustable charge pump current source module 104 is the terminal used to sample the current flowing through the current sampling resistor in the adjustable charge pump current source module 104.

[0032] The charge pump module 101 further includes a current stability controller. Since the current control transistor will adjust the opening degree in real time according to the sampled current obtained by the current sampling resistor to ensure consistency with the circuit value required by the loop compensation module 103. However, when the floating capacitor is in the discharging timing, the charging value obtained by the current sampling resistor is 0, and the current control transistor will be fully opened to increase the charging current of the capacitor. In the subsequent charging timing, when the capacitor is connected to the current mirror, it will be charged with the aforementioned maximum current. To avoid this situation, the current stability controller will maintain the opening degree of the current control transistor in the discharging timing, and will not cause the capacitor to be charged with an abnormal large current.

[0033] Error signal generation module 102 includes: a reference voltage source for outputting a reference voltage; a first sub-module, the input end of the first sub-module is adapted to be connected to the charge pump module 101; a second sub-module, the first input end of the second sub-module is connected to the output end of the first sub-module, the second input end of the second sub-module is connected to the output end of the reference voltage source, and the output end of the second sub-module is adapted to be connected to the output end of the error signal generation module 102; wherein, the first sub-module is used to obtain an input voltage and an output voltage, and obtain a voltage change amount according to the input voltage and the output voltage, and the second sub-module is used to obtain an error voltage signal according to the voltage change amount and the reference voltage.

[0034] Current signal generation module 103, the first input end of the current signal generation module 103 is connected to the output end of the second sub-module, and the second input end of the current signal generation module 103 is connected to the output end of the current holding voltage source; wherein, the current signal generation module 103 can be used to convert the error voltage signal into a current signal according to the current holding voltage, and control the adjustable charge pump current source module 104 according to the current signal. Moreover, the current signal generation module 103 can use proportional-integral compensation to convert the error voltage signal into a current signal.

[0035] The current sampling resistor is the on-resistance of the MOS transistor. The first end of the MOS transistor is connected to the second end of the current control transistor, the second end of the MOS transistor is grounded, and the control end of the MOS transistor is connected to the output end of the current holding voltage source.

[0036] The following is described in conjunction with Figure 2 the specific embodiments shown.

[0037] Specifically, in Figure 2 , C1 is the first floating capacitor, Kon1 is the first charging switch, Kon2 is the second charging switch, Koff1 is the first discharging switch, Koff2 is the second discharging switch, K1 is the current control transistor, 5 is the current sampling resistor, which is served by the MOS resistor, Vref is the reference voltage source, 1 is the first sub-module, 2 is the second sub-module, 4 is the current holding voltage source, VCP is the output voltage, PVDD is the input voltage, PGND is the ground, CPH is the first end of the first floating capacitor C1, CPL is the second end of the first floating capacitor C1, C5 is the filter capacitor, and EA_out is the current control signal output by the second sub-module 2. P1 refers to the charging phase in the switch control signal, and P2 refers to the discharging phase in the switch control signal. VDD is the preset power supply.

[0038] In Figure 2 the specific embodiment shown, the above-mentioned second sub-module 2 adopts a Type II compensation circuit.

[0039] The first sub-module 1 is specifically used to obtain the voltage change amount according to the following formula: V1 = k(VCP - PVDD), where V1 is the voltage change, k is a preset coefficient, VCP is the output voltage, and PVDD is the input voltage.

[0040] Specifically, the above-mentioned first charging switch Kon1, second charging switch Kon2, first discharging switch Koff1, and second discharging switch Koff2 are controlled by a switch control signal. The switch control signal includes a charging phase P1 and a discharging phase P2. When the current phase of the switch control signal is the charging phase P1, the operating timing of the charge pump module 101 is the charging timing. When the current phase of the switch control signal is the discharging phase P2, the operating timing of the charge pump module 101 is the discharging timing.

[0041] During the charging timing, the first charging switch Kon1 and the second charging switch Kon2 are closed, the first discharging switch Koff1 and the second discharging switch Koff2 are opened, and PVDD charges the first floating capacitor C1. During the discharging timing, the first charging switch Kon1 and the second charging switch Kon2 are opened, the first discharging switch Koff1 and the second discharging switch Koff2 are closed, and the first floating capacitor C1 discharges to output VCP.

[0042] Thus, by setting appropriate charging timing duration and discharging timing duration, VCP can be made the target voltage.

[0043] Moreover, the first sub-module 1 is also set to collect VCP and PVDD to obtain the voltage change V1 = k(VCP - PVDD).

[0044] Through this voltage change, the difference between VCP and PVDD can be obtained. If this difference changes, it indicates that the output voltage VCP fluctuates.

[0045] Therefore, after obtaining k(VCP - PVDD), k(VCP - PVDD) can be compared with the reference voltage Vref, and a Type II compensation circuit is used to perform integral compensation to obtain the error voltage signal EA_out.

[0046] After obtaining the error voltage signal EA_out, the adjustable charge pump current source is controlled to obtain the required charging current. Thus, it is realized to control the charge pump module 101 to charge the floating capacitor during the charging timing. The output terminal of the current holding voltage source 4 is also connected to the first end of the current sampling resistor 5. The current holding voltage source 4 outputs a current holding voltage to the current sampling resistor 5, so that the current sampling resistor 5 maintains an appropriate voltage bias during the discharging timing, avoiding abnormal increase of the current.

[0047] Among them, the above reference voltage Vref is compared with the difference between the target voltage and the input voltage PVDD. The second sub-module 2 can determine whether the output voltage VCP fluctuates based on the above k(VCP - PVDD) and the reference voltage Vref, and when a fluctuation occurs, output a corresponding error voltage signal. For example, if it is determined that the output voltage VCP decreases, an error voltage signal EA_out for controlling the increase of the corresponding charging current of the current control transistor K1 in the charging timing can be output; if it is determined that the output voltage VCP increases, an error voltage signal EA_out for controlling the decrease of the corresponding charging current of the current control transistor K1 in the charging timing can be output.

[0048] Moreover, since the current can reach several hundred mA or several A when the charge pump starts or is heavily loaded, in integrated circuit design, ordinary resistors need to be very wide to meet such requirements. Therefore, the current sampling resistor 5 is used. For example, a MOS transistor can be used, and the on-resistance of the MOS transistor is used to replace the sampling resistor.

[0049] Moreover, since the current flowing through the current sampling resistor 5 is 0 during the discharge process of the floating capacitor C1 to the external capacitor, that is, the on-current of the current sampling resistor 5 is 0, the current control circuit will increase the charging amount to maintain the output voltage at the target voltage, which will cause the loop to deviate from the expected setting. Therefore, the current holding voltage source 4 is added to achieve current holding during the discharge timing, that is, the voltage is output through the current holding voltage source 4 during the discharge timing, so that the on-current of the current sampling resistor 5 during the discharge timing is the same as the on-current during the charging timing, avoiding the interference of the actual current value 0 to the system.

[0050] Moreover, by collecting the on-current of the current sampling resistor 5, the actual charging condition of the first floating capacitor C1 can be obtained, and the charging phase P1 can be controlled according to this actual charging condition, thereby adjusting the charging timing to maintain the output voltage at the target voltage.

[0051] In some embodiments of the present invention, the charge pump module 101 includes at least one floating capacitor; wherein, when the charge pump module 101 includes two floating capacitors, the charge pump module 101 includes a second floating capacitor and a third floating capacitor, and the charge pump module 101 further includes: a third discharge switch, the first end of the third discharge switch is connected to the first end of the second floating capacitor; a fourth discharge switch, the first end of the fourth discharge switch is connected to the second end of the second floating capacitor, and the second end of the fourth discharge switch is connected to the first section of the third floating capacitor; a fifth discharge switch, the first end of the fifth discharge switch is connected to the second end of the third floating capacitor, and the second end of the fifth discharge switch is adapted to be connected to the output end of the charge pump module 101; a third charging switch, the first end of the third charging switch is connected to the first end of the second floating capacitor; a fourth charging switch, the first end of the fourth charging switch is connected to the second end of the second floating capacitor; a fifth charging switch, the first end of the fifth charging switch is connected to the second end of the fourth discharge switch; a sixth charging switch, the first end of the sixth charging switch is connected to the second end of the third floating capacitor, and the second end of the sixth charging switch is connected to the second end of the fourth charging switch; wherein, the second end of the third discharge switch and the second end of the fourth charging switch are connected and are adapted to be connected to a preset voltage source, the second end of the third charging switch and the second end of the fifth charging switch are connected and are adapted to be connected to the adjustable charge pump current source module 104, and the third charging switch, the fourth charging switch, the fifth charging switch and the sixth charging switch are used to be closed during the charging timing to charge the second floating capacitor and the third floating capacitor by using the preset voltage source under the control of the adjustable charge pump current source.

[0052] The charge pump module 101 further includes: a first capacitor, the first end of the first capacitor is connected to the second end of the sixth charging switch and is adapted to be connected to a preset voltage source, and the second end of the first capacitor is connected to the second end of the fifth discharge switch and is adapted to be connected to the output end of the charge pump module 101.

[0053] The error signal generation module 102 includes: a reference voltage source for outputting a reference voltage; a first sub-module, the first input end of the first sub-module is adapted to be connected to the first input end of the error signal generation module 102, and the second input end of the first sub-module is adapted to be connected to the second input end of the error signal generation module 102; a second sub-module, the first input end of the second sub-module is connected to the output end of the first sub-module, the second input end of the second sub-module is connected to the output end of the reference voltage source, and the output end of the second sub-module is adapted to be connected to the output end of the error signal generation module 102; wherein, the first sub-module is used to obtain a voltage change amount according to the input voltage and the output voltage, and the second sub-module is used to obtain an error voltage signal according to the voltage change amount and the voltage value of the reference voltage, and control the charge pump module 101 according to the error voltage signal to achieve loop compensation.

[0054] The first input terminal of the current signal generation module 103 is connected to the output terminal of the second sub-module, and the second input terminal of the current signal generation module 103 is connected to the output terminal of the current holding voltage source; wherein, the current signal generation module 103 is used to convert the error voltage signal into a current signal according to the current holding voltage, and control the adjustable charge pump current source module 104 according to the current signal to achieve loop compensation.

[0055] The following is described in conjunction with Figure 3 the specific embodiments shown below.

[0056] Specifically, in Figure 3 , C2 is the second floating capacitor, C3 is the third floating capacitor, Kon3 is the third charging switch, Kon4 is the fourth charging switch, Kon5 is the fifth charging switch, Kon6 is the sixth charging switch, Koff3 is the third discharging switch, Koff4 is the fourth discharging switch, Koff5 is the fifth discharging switch, CPL1 is the first end of the second floating capacitor C2, CPH1 is the second end of the second floating capacitor C2, CPL2 is the first end of the third floating capacitor C3, CPH2 is the second end of the third floating capacitor C3, 5 is the current sampling resistor, which is composed of a MOS resistor, Vref is the reference voltage source, 1 is the first sub-module, 2 is the second sub-module, 4 is the current holding voltage source, VCP is the output voltage, PVDD is the input voltage, PGND is the ground, and EA_out is the error voltage signal.

[0057] In Figure 3 the specific embodiment shown, the above-mentioned second sub-module 2 adopts a Type II compensation circuit.

[0058] The first sub-module 1 is specifically used to obtain the voltage change amount according to the following formula: V1 = k (VCP - PVDD), wherein, V1 is the voltage change amount, k is a preset coefficient, VCP is the output voltage, and PVDD is the input voltage.

[0059] Specifically, the above-mentioned third charging switch Kon3, fourth charging switch Kon4, fifth charging switch Kon5, sixth charging switch Kon6, third discharging switch Koff3, fourth discharging switch Koff4, and fifth discharging switch Koff5 are controlled by a switch control signal, and the switch control signal includes a charging phase P1 and a discharging phase P2. When the current phase of the switch control signal is the charging phase P1, the working timing of the charge pump module 101 is the charging timing, and when the current phase of the switch control signal is the discharging phase P2, the working timing of the charge pump module 101 is the discharging timing.

[0060] In the charging timing sequence, the third charging switch Kon3, the fourth charging switch Kon4, the fifth charging switch Kon5, and the sixth charging switch Kon6 are closed, and the third discharging switch Koff3, the fourth discharging switch Koff4, and the fifth discharging switch Koff5 are open. At this time, the second floating capacitor C2 and the third floating capacitor C3 are in parallel, and PVDD charges the two floating capacitors simultaneously.

[0061] In the discharging timing sequence, the third charging switch Kon3, the fourth charging switch Kon4, the fifth charging switch Kon5, and the sixth charging switch Kon6 are open, and the third discharging switch Koff3, the fourth discharging switch Koff4, and the fifth discharging switch Koff5 are closed. At this time, the second floating capacitor C2 and the third floating capacitor C3 are in series and discharge together to output VCP. Thus, the increased voltage is twice that of a single capacitor, and a higher output voltage can be obtained. Similarly, a multi-stage capacitor charge-discharge circuit can obtain a higher output voltage.

[0062] Thus, by setting appropriate charging and discharging timing durations, VCP can reach the target voltage.

[0063] Moreover, the first sub-module 1 is also set to collect VCP and PVDD to obtain the voltage change amount V1 = k(VCP - PVDD).

[0064] Through this voltage change amount, the difference between VCP and PVDD can be obtained. If this difference changes, it indicates that the output voltage VCP fluctuates.

[0065] Therefore, after obtaining k(VCP - PVDD), k(VCP - PVDD) can be compared with the reference voltage Vref, and a Type II compensation circuit is used to perform integral compensation to obtain the error voltage signal EA_out.

[0066] After obtaining the error voltage signal EA_out, a current source is controlled to obtain the required charging current. Thus, it is realized to control the charge pump module 101 to charge the floating capacitor. The current-holding voltage source 4 outputs a maintenance voltage to maintain a proper voltage bias for the current source during the discharging timing sequence, avoiding abnormal increase in current.

[0067] Among them, the reference voltage Vref is compared with the difference between the target voltage and the input voltage PVDD. The second sub-module 2 can determine whether the output voltage VCP fluctuates based on the above k(VCP - PVDD) and the reference voltage Vref, and when a fluctuation occurs, output a corresponding error voltage signal. For example, if it is determined that the output voltage VCP decreases, an error voltage signal EA_out for controlling the increase of the corresponding charging current and the third charging current of the current control transistor K1 in the charging timing can be output. If it is determined that the output voltage VCP increases, an error voltage signal EA_out for controlling the decrease of the corresponding charging current of the current control transistor K1 in the charging timing can be output.

[0068] Moreover, since the current can reach several hundred mA or several A when the charge pump starts or is heavily loaded, in integrated circuit design, ordinary resistors need to have a very large width to meet such requirements. Therefore, the current sampling resistor 5 is used. For example, a MOS transistor can be used, and the on-resistance of the MOS transistor is used to replace the sampling resistor.

[0069] Moreover, since the current flowing through the current sampling resistor 5 is 0 during the discharge process of the floating capacitor C1 to the external capacitor, that is, the on-current of the current sampling resistor 5 is 0, the current control circuit will increase the charging amount to maintain the output voltage at the target voltage, which will cause the loop to deviate from the expected setting. Therefore, the current holding voltage source 4 is added to achieve current holding during the discharge timing, that is, the voltage is output through the current holding voltage source 4 during the discharge timing, so that the on-current of the current sampling resistor 5 during the discharge timing is the same as the on-current during the charging timing, avoiding the interference of the actual current value 0 to the system.

[0070] Moreover, by collecting the on-current of the current sampling resistor 5, the actual charging condition of the first floating capacitor C1 can be obtained, and the charging phase P1 can be controlled according to this actual charging condition, thereby adjusting the charging timing to maintain the output voltage at the target voltage.

[0071] In summary, the current-controlled fixed-voltage output charge pump circuit according to the embodiments of the present invention includes: a charge pump module, the power supply terminal of the charge pump module is connected to a preset voltage source, and the charge pump module is used to charge the floating capacitor in the charge pump module with the preset voltage source during the charging timing, discharge the floating capacitor during the discharging timing, and use the discharge voltage of the floating capacitor as the output voltage of the charge pump module; an error signal generation module, the first input terminal of the error signal generation module is connected to the output terminal of the charge pump module, and the second input terminal of the error signal generation module is connected to the power supply terminal of the charge pump module. The error signal generation module is used to obtain the input voltage and output voltage of the charge pump module, and obtain an error voltage signal according to the output voltage and the input voltage; a current signal generation module, the input terminal of the current signal generation module is connected to the output terminal of the error signal generation module, and the current signal generation module is used to compensate the current signal according to the error voltage signal to obtain a compensated current signal; an adjustable charge pump current source module, the output terminal of the adjustable charge pump current source module is connected to the control terminal of the charge pump module, and the control terminal of the adjustable charge pump current source module is connected to the output terminal of the current signal generation module. The adjustable charge pump current source module is used to control the charging current intensity when the charge pump module charges the floating capacitor under the control of the current signal to achieve a fixed voltage output. Thus, by setting the error signal generation module, the current signal generation module, and the adjustable charge pump current source module, a stable output voltage can be obtained only by transforming the input voltage once, with high efficiency and low heat generation.

[0072] Furthermore, the present invention proposes a charge pump system.

[0073] Figure 4 It is a structural block diagram of the charge pump system according to the embodiments of the present invention.

[0074] As Figure 4 shown, the charge pump system 10 includes the above-mentioned current-controlled fixed-voltage output charge pump circuit 100.

[0075] According to the charge pump system of the embodiments of the present invention, through the above-mentioned current-controlled fixed-voltage output charge pump circuit, a stable output voltage can be obtained only by transforming the input voltage once, with high efficiency and low heat generation.

[0076] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein can be considered as a definite sequence list of executable instructions for implementing logical functions, which can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or used in combination with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other appropriate processing as necessary, and then stored in a computer memory.

[0077] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented using hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), and the like.

[0078] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0079] In the description of this specification, the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as a limitation on the present invention.

[0080] In addition, the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0081] In the description of this specification, unless otherwise stated, terms such as "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0082] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0083] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as a limitation on the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A current-controlled fixed voltage output charge pump circuit, characterized in that: The circuit comprises: A charge pump module, wherein a first end of the charge pump module is connected to a preset voltage source, and a second end of the charge pump module is connected to an adjustable charge pump current source module, and the charge pump module is used to charge a floating capacitor in the charge pump module using the preset voltage source and the adjustable charge pump current source module in a charging sequence, discharge the floating capacitor in a discharging sequence, and use the discharge voltage of the floating capacitor as the output voltage of the charge pump module; an error signal generating module, connected to the charge pump module, and configured to obtain an error voltage signal according to an input voltage and an output voltage of the charge pump module; A current signal generating module, connected to the error signal generating module, the current signal generating module is used to obtain a current signal according to the error voltage signal, wherein the current signal is a signal for controlling the adjustable charge pump current source module; The adjustable charge pump current source module is connected to the charge pump module and the current signal generating module. The adjustable charge pump current source module is used to control the charging current intensity of the charge pump module when charging the floating capacitor under the control of the current signal to achieve a fixed voltage output.

2. The current-controlled fixed-voltage output charge pump circuit according to claim 1, characterized in that: The charge pump module includes a first floating capacitor, and the charge pump module further includes: a first charging switch, wherein a first end of the first charging switch is connected to a first end of the first floating capacitor; a second charging switch, wherein a first end of the second charging switch is connected to a second end of the first floating capacitor, and a second end of the second charging switch is suitable for connecting to the adjustable charge pump current source module; a first discharge switch, wherein a first end of the first discharge switch is connected to a second end of the first floating capacitor; a second discharge switch, wherein a first end of the second discharge switch is connected to a first end of the first floating capacitor, and a second end of the second discharge switch is suitable for connecting to an output end of the charge pump module; Among them, the second end of the first charging switch and the second end of the first discharging switch are connected and suitable for connecting to the preset voltage source, the first charging switch and the second charging switch are used to close in the charging timing to charge the first floating capacitor using the preset voltage source under the control of the adjustable charge pump current source module, and the first discharging switch and the second discharging switch are used to close in the discharging timing to discharge the first floating capacitor.

3. The current-controlled fixed-voltage output charge pump circuit according to claim 2, characterized in that: The adjustable charge pump current source module comprises: A current control tube, wherein a first end of the current control tube is suitable for connecting to the charge pump module, and a control end of the current control tube is suitable for connecting to the current signal generating module; A current sampling resistor, wherein a first end of the current sampling resistor is connected to a second end of the current control tube, and a second end of the current sampling resistor is grounded; The current control tube is used to adjust the current intensity flowing through itself according to the current signal and the sampling current to control the charging current intensity when charging the floating capacitor. The sampling current is the current flowing through the current sampling resistor.

4. The current-controlled fixed-voltage output charge pump circuit according to claim 1, characterized in that: The error signal generating module comprises: A reference voltage source, used for outputting a reference voltage; A first submodule, wherein an input terminal of the first submodule is suitable for connecting to the charge pump module; a second submodule, wherein a first input terminal of the second submodule is connected to an output terminal of the first submodule, a second input terminal of the second submodule is connected to the reference voltage source, and an output terminal of the second submodule is suitable for connecting to an output terminal of the error signal generating module; The first submodule is used to obtain the input voltage and the output voltage, and obtain a voltage variation according to the input voltage and the output voltage, and the second submodule is used to obtain the error voltage signal according to the voltage variation and the reference voltage.

5. The current-controlled fixed-voltage output charge pump circuit according to claim 4, characterized in that: The first input terminal of the current signal generating module is connected to the output terminal of the second submodule, and the second input terminal of the current signal generating module is connected to the current holding voltage source; The current signal generating module is used to convert the error voltage signal into a current signal according to the current holding voltage output by the current holding voltage source, and control the adjustable charge pump current source module according to the current signal.

6. The current-controlled fixed-voltage output charge pump circuit according to claim 1, characterized in that: The charge pump module includes at least one floating capacitor; Wherein, when the charge pump module includes two floating capacitors, the charge pump module includes a second floating capacitor and a third floating capacitor, and the charge pump module further includes: a third discharge switch, a first end of the third discharge switch being connected to a first end of the second floating capacitor; a fourth discharge switch, wherein a first end of the fourth discharge switch is connected to the second end of the second floating capacitor, and a second end of the fourth discharge switch is connected to the first end of the third floating capacitor; a fifth discharge switch, wherein a first end of the fifth discharge switch is connected to a second end of the third floating capacitor, and a second end of the fifth discharge switch is suitable for connecting to an output end of the charge pump module; a third charging switch, a first end of the third charging switch being connected to a first end of the second floating capacitor; a fourth charging switch, wherein a first end of the fourth charging switch is connected to a second end of the second floating capacitor; a fifth charging switch, wherein a first end of the fifth charging switch is connected to a second end of the fourth discharging switch; a sixth charging switch, wherein a first end of the sixth charging switch is connected to the second end of the third floating capacitor, and a second end of the sixth charging switch is connected to the second end of the fourth charging switch; Among them, the second end of the third discharge switch is connected to the second end of the fourth charging switch and is suitable for connecting to the preset voltage source, the second end of the third charging switch is connected to the second end of the fifth charging switch and is suitable for connecting to the adjustable charge pump current source module, the third discharge switch, the fourth discharge switch and the fifth discharge switch are used to close in the discharge timing to discharge the second floating capacitor and the third floating capacitor, the third charging switch, the fourth charging switch, the fifth charging switch and the sixth charging switch are used to close in the charging timing to charge the second floating capacitor and the third floating capacitor using the preset voltage source under the control of the adjustable charge pump current source.

7. The current-controlled fixed-voltage output charge pump circuit according to claim 6, characterized in that: The charge pump module further includes: A first capacitor, wherein the first end of the first capacitor is connected to the second end of the sixth charging switch and is suitable for connecting to the preset voltage source, and the second end of the first capacitor is connected to the second end of the fifth discharging switch and is suitable for connecting to the output end of the charge pump module.

8. The current-controlled fixed-voltage output charge pump circuit according to claim 4, characterized in that: The first submodule is specifically used to obtain the voltage change according to the following formula: V1=k(VCP-PVDD), Among them, V1 is the voltage change, k is a preset coefficient, VCP is the output voltage, and PVDD is the input voltage.

9. The current-controlled fixed-voltage output charge pump circuit according to claim 2, characterized in that: The current sampling resistor is the on-resistance of the MOS tube, the first end of the MOS tube is connected to the second end of the current control tube, the second end of the MOS tube is grounded, and the control end of the MOS tube is connected to the output end of the current holding voltage source.

10. A charge pump system, characterized in that: A charge pump circuit comprising a current-controlled fixed voltage output according to any one of claims 1 to 9.

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