Charge pump device, method of operating the same and application circuit

Abstract

The present application provides a charge pump device, an operating method thereof and an application circuit. The charge pump device includes a switch, a charge pump circuit, a rotation rate control circuit and a comparison circuit. The charge pump circuit generates an output voltage based on performing a pump operation on a power supply voltage by a clock signal of the switch turned on. The comparison circuit checks a first reference voltage with a rotation rate generated by the rotation rate control circuit and a second reference voltage with a fixed level. When the first reference voltage has not reached the second reference voltage, the comparison circuit decides whether to turn on the switch based on the first reference voltage and the output voltage. When the first reference voltage has reached the second reference voltage, the comparison circuit decides whether to turn on the switch based on the second reference voltage and the output voltage.

Description

Technical Field

[0001] This invention relates to a voltage generation circuit, and more particularly to a charge pump device, its operation method, and its application circuit. Background Technology

[0002] Charge pumps are responsible for providing high voltages in many application circuits. For example, in flash memory, charge pumps provide high voltages to memory cells for operations such as programming, erasing, and reading. In application circuits, multiple charge pumps often perform pumping operations on the same power supply voltage VDD, generating different high voltages. When multiple charge pumps operate simultaneously, the peak current of these pumps can be very large, causing a power drop in the power supply voltage VDD, which can lead to system interference and malfunctions. Summary of the Invention

[0003] The present invention provides a charge pump device, its operation method and application circuit, which generates an output voltage by performing pump operation on the power supply voltage based on the triggering of a clock signal.

[0004] In one embodiment, the charge pump device includes a switch, a charge pump circuit, a slew rate control circuit, and a comparator circuit. A first terminal of the switch receives a clock signal. A clock terminal of the charge pump circuit is coupled to a second terminal of the switch. An input terminal of the charge pump circuit receives a power supply voltage. In response to the switch being on, the charge pump circuit performs a pumping operation on the power supply voltage based on the clock signal at the clock terminal to generate an output voltage. The slew rate control circuit generates a first reference voltage having a slew rate. A comparator circuit is coupled to the slew rate control circuit to receive the first reference voltage. The comparator circuit is coupled to the output terminal of the charge pump circuit to receive the output voltage. The comparator circuit is coupled to the control terminal of the switch. The comparator circuit checks the first reference voltage against a second reference voltage having a fixed level. In response to the first reference voltage not reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a first level relationship between the first reference voltage and the output voltage. In response to the first reference voltage reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a second level relationship between the second reference voltage and the output voltage.

[0005] In one embodiment, the above-described operation method includes: receiving a clock signal from a first terminal of a switch of a charge pump device; receiving a power supply voltage from an input terminal of a charge pump circuit of the charge pump device, wherein the clock terminal of the charge pump circuit is coupled to a second terminal of the switch; generating a first reference voltage having a slew rate by a slew rate control circuit of the charge pump device; checking the first reference voltage against a second reference voltage having a fixed level by a comparator circuit of the charge pump device; determining whether to turn on the switch based on a first level relationship between the first reference voltage and the output voltage in response to the first reference voltage not reaching the second reference voltage; determining whether to turn on the switch based on a second level relationship between the second reference voltage and the output voltage in response to the first reference voltage reaching the second reference voltage; and generating an output voltage by the charge pump circuit performing a pump operation on the power supply voltage based on the clock signal of the clock terminal when the switch is on.

[0006] In one embodiment, the application circuit described above includes multiple charge pump devices. These charge pump devices receive a common power supply voltage at their inputs. These charge pump devices perform pumping operations on the power supply voltage based on a clock signal triggering, thereby generating multiple output voltages with dispersed slew rates.

[0007] Based on the above, the application circuits of various embodiments of the present invention include multiple charge pump devices, each of which can generate an output voltage by performing a pumping operation on the power supply voltage based on a clock signal trigger. A slew rate control circuit generates a first reference voltage with a controllable slew rate. When the first reference voltage has not reached a certain default fixed voltage (second reference voltage), the conduction of the switch is based on the level relationship between the first reference voltage and the output voltage. When the switch is on, the charge pump circuit performs a pumping operation based on a clock signal to generate an output voltage. Therefore, the charge pump device raises (or lowers) the output voltage with a controllable slew rate during the initial power-on phase. When the first reference voltage has reached the second reference voltage, the conduction of the switch is based on the level relationship between the second reference voltage and the output voltage. Therefore, the charge pump device can maintain the output voltage at the target level after the initial power-on phase ends. In application scenarios where multiple charge pump devices are used simultaneously, different charge pump devices can be set with different slew rates (dispersing the slew rate) to generate different output voltages with dispersed rise (or fall) rates during the initial power-on phase. Therefore, when multiple charge pump devices are powered on simultaneously, the peak power current can be effectively reduced because the different output voltages of these charge pump devices have a dispersed slew rate in the initial stage of power-on. Attached Figure Description

[0008] Figure 1 This is a block diagram of an application circuit according to one embodiment;

[0009] Figure 2This is a waveform diagram of the output voltage and power supply current of multiple charge pumps operating simultaneously during the initial power-on phase.

[0010] Figure 3 This is a block diagram of a charge pump device according to an embodiment of the present invention;

[0011] Figure 4 This is a schematic flowchart of an operation method of a charge pump device according to an embodiment of the present invention;

[0012] Figure 5 This is a schematic diagram of the waveforms of the output voltage, reference voltage, reference voltage, and power supply current of the charge pump device in the initial stage of power-on, according to an embodiment of the present invention.

[0013] Figure 6 This is a block diagram of a comparison circuit according to an embodiment of the present invention;

[0014] Figure 7 This is a block diagram of a slew rate control circuit according to an embodiment of the present invention.

[0015] Explanation of icon numbers

[0016] 110, 120, 130: Charge pump device

[0017] 210: Upper part

[0018] 220: Lower part

[0019] 300: Charge pump device

[0020] 310: Charge pump circuit

[0021] 320: Slew rate control circuit

[0022] 330: Comparator Circuit

[0023] 331: Feedback Circuit

[0024] C31: Output capacitor

[0025] C71: Capacitor

[0026] CLK: Clock signal

[0027] CM71: Current Mirror

[0028] CMP6: Comparator

[0029] CS71: Current Source

[0030] GND: Grounding voltage

[0031] Ipeak: Peak value

[0032] Ivdd1, Ivdd3: Power supply current

[0033] M71, M72: Transistors

[0034] R61, R62: Resistors

[0035] S410~S470: Steps

[0036] SRVREF, VREF: Reference voltage

[0037] SW31: Switch

[0038] VDD: Power supply voltage

[0039] VOUT11, VOUT12, VOUT13, VOUT3: Output voltage Detailed Implementation

[0040] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same element references are used in the drawings and description to denote the same or similar parts.

[0041] Figure 1 This is a block diagram of an application circuit according to one embodiment. Figure 1 In the example, the application circuit is assumed to have three sets of charge pump devices 110, 120, and 130. The inputs of charge pump devices 110, 120, and 130 receive the same power supply voltage VDD. In the application circuit, charge pump devices 110, 120, and 130 perform pumping operations on the power supply voltage VDD to generate output voltages VOUT11, VOUT12, and VOUT13 with different levels. When charge pump devices 110, 120, and 130 are powered on simultaneously, the peak value of the power supply current Ivdd1 will be very large, causing a non-negligible power drop in the power supply voltage VDD.

[0042] Figure 2 This is a waveform diagram of the output voltages VOUT11, VOUT12, and VOUT13 and the power supply current Ivdd1 of multiple charge pump devices 110, 120, and 130 during the initial power-on phase when multiple charge pump devices 110, 120, and 130 operate simultaneously. Figure 2 The horizontal axis represents time. Figure 2The upper part 210 shows that after the charge pump devices 110, 120, and 130 are simultaneously powered on, they simultaneously perform pumping operations on the power supply voltage VDD to generate different output voltages VOUT11, VOUT12, and VOUT13. When the charge pump devices 110, 120, and 130 are powered on simultaneously, they will exert their full strength to raise the output voltages VOUT11, VOUT12, and VOUT13 to different default voltage levels. Generally, the rise rate, also known as the slew rate, of the output voltages VOUT11, VOUT12, and VOUT13 is basically similar to each other. In this case, the charge pump devices 110, 120, and 130 will consume a large current in the initial stage of power-on. Figure 2 The upper part 210 shows Figure 1 The power supply current Ivdd1 is shown. Because charge pump devices 110, 120, and 130 raise the output voltages VOUT11, VOUT12, and VOUT13 with similar slew rates, the peak value of the power supply current Ivdd1 (i.e., the sum of the currents consumed by charge pump devices 110, 120, and 130) will be very large, causing a significant drop in the power supply voltage VDD, which in turn causes system interference and malfunctions.

[0043] Figure 3 This is a circuit block diagram of a charge pump device 300 according to an embodiment of the present invention. Please refer to... Figure 3 Triggered by the clock signal CLK, the charge pump device 300 performs a pumping operation on the power supply voltage VDD to generate a pump voltage (output voltage VOUT3). The charge pump device 300 can be used in various application circuits to provide the output voltage VOUT3. For example (but not limited to), the charge pump device 300 can be used in flash memory to provide the output voltage VOUT3 for memory cells to perform operations such as programming, erasing, and reading. In this embodiment of the invention, the charge pump device 300 raises (or lowers) the output voltage VOUT3 at a controllable slew rate during the initial power-on phase. Therefore, in applications using multiple charge pump devices 300 simultaneously, different charge pump devices 300 can be set to different slew rates (dispersing the slew rate) to generate different output voltages VOUT3 with different rise (or fall) rates during the initial power-on phase. "Dispersing the slew rate" means increasing the difference in slew rates between different charge pump devices.

[0044] exist Figure 3In the illustrated embodiment, the charge pump device 300 includes a switch SW31, a charge pump circuit 310, a slew rate control circuit 320, a comparator circuit 330, and an output capacitor C31. This embodiment does not limit the specific implementation of the switch SW31. For example, the switch SW31 may include a switching transistor, a transmission gate, a logic gate, or other switching circuits (or switching components). Taking a logic gate as an example, the first input terminal of the logic gate serves as the first terminal of the switch SW31, the second input terminal of the logic gate serves as the control terminal of the switch SW31, and the output terminal of the logic gate serves as the second terminal of the switch SW31. Depending on the actual design, the logic gate may include an AND gate, a NAND gate, or other logic gates.

[0045] The first terminal of switch SW31 receives the clock signal CLK. The clock terminal of charge pump circuit 310 is coupled to the second terminal of switch SW31. The input terminal of charge pump circuit 310 receives the power supply voltage VDD. The first terminal of output capacitor C31 is coupled to the output terminal of charge pump circuit 310. The second terminal of output capacitor C31 is coupled to a reference voltage (e.g., ground voltage GND or other fixed voltage). In response to switch SW31 being on, charge pump circuit 310 performs a pumping operation on power supply voltage VDD based on the clock signal CLK at the clock terminal to generate output voltage VOUT3. In response to switch SW31 being off, charge pump circuit 310 stops performing a pumping operation on power supply voltage VDD due to the disappearance of clock signal CLK.

[0046] Figure 4 This is a schematic flowchart illustrating the operation method of a charge pump device according to an embodiment of the present invention. Please refer to... Figure 3 and Figure 4 In step S410, the first terminal of switch SW31 receives the clock signal CLK, and the input terminal of charge pump circuit 310 receives the power supply voltage VDD. In step S420, slew rate control circuit 320 generates a reference voltage SRVREF with slew rate (in the initial power-on phase, the slew rate of reference voltage SRVREF is not 0). The first input terminal of comparator circuit 330 is coupled to the output terminal of slew rate control circuit 320 to receive the reference voltage SRVREF. The second input terminal of comparator circuit 330 is coupled to the output terminal of charge pump circuit 310 to receive the output voltage VOUT3. The output terminal of comparator circuit 330 is coupled to the control terminal of switch SW31. In step S430, comparator circuit 330 checks the reference voltage SRVREF (first reference voltage) against a reference voltage VREF (second reference voltage) with a fixed level.

[0047] In response to the initial power-up condition where the reference voltage SRVREF has not reached the reference voltage VREF (i.e., SRVREF < VREF, the judgment result of step S440 is "No"), the charge pump device 300 proceeds to step S450. In step S450, the comparator circuit 330 determines whether to turn on the switch SW31 based on a first level relationship between the reference voltage SRVREF and the output voltage VOUT3. In response to the initial power-up condition where the reference voltage SRVREF has reached the reference voltage VREF (i.e., SRVREF ≥ VREF, the judgment result of step S440 is "Yes"), the charge pump device 300 proceeds to step S460. In step S460, the comparator circuit 330 determines whether to turn on the switch SW31 based on a second level relationship between the reference voltage VREF and the output voltage VOUT3.

[0048] In step S470, when switch SW31 is turned on, charge pump circuit 310 performs pumping operation on power supply voltage VDD based on clock signal CLK to generate output voltage VOUT3. When switch SW31 is turned off, charge pump circuit 310 stops pumping operation on power supply voltage VDD due to the disappearance of clock signal CLK.

[0049] Figure 5 This is a schematic diagram of the waveforms of the output voltage VOUT3, reference voltage VREF, reference voltage SRVREF, and power supply current Ivdd3 of the charge pump device 300 during the initial power-on phase, according to an embodiment of the present invention. Figure 5 The horizontal axis represents time. Figure 5 The upper part shows the output voltage VOUT3 generated by the charge pump circuit 310 performing pump operation on the power supply voltage VDD after the charge pump device 300 is powered on. Figure 5 The middle section shows the reference voltage VREF and the reference voltage SRVREF after the charge pump device 300 is powered on. The reference voltage SRVREF has a controllable slew rate in the initial stage of power-on (described in detail later). The reference voltage VREF has a fixed level (e.g., 1.2 volts, but not limited thereto). Figure 5 The lower part shows Figure 3 The power supply current shown is Ivdd3.

[0050] In response to the initial power-up condition where the reference voltage SRVREF has not reached the reference voltage VREF, the comparator circuit 330 determines whether to turn on the switch SW31 based on a first level relationship between the reference voltage SRVREF and the output voltage VOUT3. Therefore, the output voltage VOUT3 is pulled up based on the controllable slew rate of the reference voltage SRVREF. That is, the slew rate of the output voltage VOUT3 corresponds to the controllable slew rate of the reference voltage SRVREF. In response to the initial power-up condition where the reference voltage SRVREF has reached the reference voltage VREF, the comparator circuit 330 determines whether to turn on the switch SW31 based on a second level relationship between the reference voltage VREF and the output voltage VOUT3. Therefore, the charge pump circuit 310 can maintain the output voltage VOUT3 at the target level after the initial power-up condition ends. That is, the target level of the output voltage VOUT3 corresponds to the level of the reference voltage VREF.

[0051] In summary, the charge pump device 300 can generate an output voltage VOUT3 by performing a pumping operation on the power supply voltage VDD based on the triggering of the clock signal CLK. The slew rate control circuit 320 generates a reference voltage SRVREF with a controllable slew rate. When the reference voltage SRVREF has not reached a certain default fixed voltage (reference voltage VREF), the conduction of switch SW31 is based on the level relationship between the reference voltage SRVREF and the output voltage VOUT3. When switch SW31 is on, the charge pump circuit 310 performs a pumping operation based on the clock signal CLK to generate the output voltage VOUT3. Therefore, the charge pump device 300 raises (or lowers) the output voltage VOUT3 with a controllable slew rate during the initial power-on phase. Because the output voltage VOUT3 of the charge pump device 300 has a controllable slew rate during the initial power-on phase, the peak value Ipeak of the power supply current Ivdd3 can be effectively reduced. When the reference voltage SRVREF has reached the reference voltage VREF, the conduction of switch SW31 is based on the level relationship between the reference voltage VREF and the output voltage VOUT3. Therefore, the charge pump device 300 can maintain the output voltage VOUT3 at the target level after the initial power-on period.

[0052] In applications where multiple charge pump devices 300 are used simultaneously, different charge pump devices 300 can be set with different slew rates to generate different output voltages VOUT3 with different rise (or fall) rates in the initial stage of power-on. Therefore, when multiple charge pump devices 300 are powered on simultaneously, the peak value Ipeak of the power supply current Ivdd3 can be effectively reduced because these different output voltages VOUT3 have different slew rates in the initial stage of power-on.

[0053] For example, the charge pump device 300 can be used as... Figure 1This is one of many embodiments of the charge pump devices 110, 120, and 130 shown. In the implementation of charge pump device 300... Figure 1 In the application scenarios shown for each charge pump device 110, 120, and 130, the charge pump devices 110, 120, and 130 perform pumping operations on the power supply voltage VDD to generate output voltages VOUT11, VOUT12, and VOUT13 with different levels. The charge pump devices 110, 120, and 130 (multiple charge pump devices 300) can be set with different slew rates. When the charge pump devices 110, 120, and 130 are powered on simultaneously, they generate different output voltages VOUT11, VOUT12, and VOUT13 with different rise (or fall) rates in the initial stage of power-on.

[0054] Figure 2 The lower part 220 shows that Figure 3 The charge pump device 300 shown is implemented Figure 1 Examples of each charge pump device 110, 120, and 130 are shown. When charge pump devices 110, 120, and 130 are simultaneously powered on, they (multiple charge pump devices 300) simultaneously pump the power supply voltage VDD at different slew rates, generating different output voltages VOUT11, VOUT12, and VOUT13 (different default voltage levels). That is, charge pump devices 110, 120, and 130 raise the output voltages VOUT11, VOUT12, and VOUT13 at different slew rates. Figure 2 The lower part 220 shows Figure 1 The power supply current Ivdd1 is shown. Under different slew rates, the peak value of the power supply current Ivdd1 (that is, the sum of the current consumed by charge pump devices 110, 120 and 130) can be effectively reduced.

[0055] Figure 6 This is a block diagram of a comparator circuit 330 according to an embodiment of the present invention. Figure 6 In this embodiment, the comparator circuit 330 includes a feedback circuit 331 and a comparator CMP6. Please refer to... Figure 5 and Figure 6 The input of feedback circuit 331 is coupled to the output of charge pump circuit 310 to receive the output voltage VOUT3. Feedback circuit 331 generates a feedback voltage VFB based on the output voltage VOUT3. Figure 6In this embodiment, the feedback circuit 331 includes resistors R61 and R62. The first end of resistor R61 is coupled to the output of charge pump circuit 310 to receive the output voltage VOUT3. The second end of resistor R61 is coupled to the inverting input of comparator CMP6 to provide the feedback voltage VFB. The first end of resistor R62 is coupled to the second end of resistor R61. The second end of resistor R62 is coupled to a reference voltage (e.g., ground voltage GND or other fixed voltage). This embodiment does not limit the specific implementation of the feedback circuit 331. In other embodiments, the feedback circuit 331 may also directly use the output voltage VOUT3 as the feedback voltage VFB.

[0056] The first non-inverting input of comparator CMP6 is coupled to the slew rate control circuit 320 to receive the reference voltage SRVREF. The second non-inverting input of comparator CMP6 receives the reference voltage VREF. The inverting input of comparator CMP6 is coupled to the output of feedback circuit 331 to receive the feedback voltage VFB. The output of comparator CMP6 is coupled to the control terminal of switch SW31. Based on the comparison result of the reference voltage SRVREF, the feedback voltage VFB, comparator CMP6 determines whether to turn on switch SW31. For example, in response to the reference voltage SRVREF not reaching the reference voltage VREF, comparator CMP6 compares the reference voltage SRVREF with the feedback voltage VFB. In response to the feedback voltage VFB being less than the reference voltage SRVREF, comparator CMP6 turns on switch SW31. In response to the feedback voltage VFB being greater than the reference voltage SRVREF, comparator CMP6 turns off switch SW31.

[0057] In response to the reference voltage SRVREF reaching the reference voltage VREF, comparator CMP6 compares the reference voltage VREF with the feedback voltage VFB. In response to the feedback voltage VFB being less than the reference voltage VREF, comparator CMP6 turns on switch SW31. In response to the feedback voltage VFB being greater than the reference voltage VREF, comparator CMP6 turns off switch SW31.

[0058] Figure 7 This is a block diagram of a slew rate control circuit 320 according to an embodiment of the present invention. Figure 7In this embodiment, the slew rate control circuit 320 includes a current mirror CM71, a current source CS71, and a capacitor C71. The current mirror CM71 has a main current path and a secondary current path, wherein a first end of the main current path and a first end of the secondary current path receive the power supply voltage VDD. The current source CS71 is coupled to a second end of the main current path of the current mirror CM71. A first end of the capacitor C71 is coupled to a second end of the secondary current path of the current mirror CM71. A second end of the capacitor C71 is coupled to a reference voltage (e.g., ground voltage GND or other fixed voltage). During the initial power-up phase of the power supply voltage VDD, the second end of the secondary current path of the current mirror CM71 generates a reference voltage SRVREF with slew rate for the comparator circuit 330.

[0059] exist Figure 7 In this embodiment, the current mirror CM71 includes transistors M71 and M72. Transistor M71 provides the main current path for the current mirror CM71, while transistor M72 provides the secondary current path for the current mirror CM71. A first terminal (e.g., the source) of transistor M71 serves as the first terminal of the main current path. A second terminal (e.g., the drain) of transistor M71 serves as the second terminal of the main current path. A control terminal (e.g., the gate) of transistor M71 is coupled to the second terminal of transistor M71. A first terminal (e.g., the source) of transistor M72 serves as the first terminal of the secondary current path. A second terminal (e.g., the drain) of transistor M72 serves as the second terminal of the secondary current path. A control terminal (e.g., the gate) of transistor M72 is coupled to the control terminal of transistor M71.

[0060] exist Figure 7 In this embodiment, the reference voltage SRVREF can provide different slew rates according to design requirements, based on the current multiplier of the current mirror CM71, the current of the current source CS71, or the capacitance value of the capacitor C71. Furthermore, to increase design flexibility, in other embodiments, transistor M72 can be a variable transistor (i.e., the effective channel aspect ratio of transistor M72 is adjustable) to adjust the current multiplier of the current mirror CM71 according to different application scenarios, thereby adjusting the slew rate of the reference voltage SRVREF; or, capacitor C71 can be a variable capacitor (i.e., the equivalent capacitance value of capacitor C71 is adjustable) to adjust the capacitance value of capacitor C71 according to different application scenarios, thereby adjusting the slew rate of the reference voltage SRVREF.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A charge pump device for generating an output voltage by performing a pumping operation on a power supply voltage based on a clock signal triggering the pump, characterized in that, The charge pump device includes: A switch having a first terminal that receives the clock signal; A charge pump circuit has a clock terminal coupled to a second terminal of the switch, wherein the input terminal of the charge pump circuit receives the power supply voltage, and the charge pump circuit generates the output voltage by performing the pumping operation on the power supply voltage based on the clock signal of the clock terminal when the switch is turned on; The slew rate control circuit generates a first reference voltage with slew rate; and A comparator circuit is coupled to the slew rate control circuit to receive the first reference voltage, coupled to the output of the charge pump circuit to receive the output voltage, and coupled to the control terminal of the switch, wherein the comparator circuit checks the first reference voltage against a second reference voltage having a fixed level. In response to the first reference voltage not reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a first level relationship between the first reference voltage and the output voltage; and In response to the first reference voltage reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a second level relationship between the second reference voltage and the output voltage.

2. The charge pump device according to claim 1, characterized in that, The switch includes: A logic gate, wherein the first input terminal of the logic gate serves as the first terminal of the switch, the second input terminal of the logic gate serves as the control terminal of the switch, and the output terminal of the logic gate serves as the second terminal of the switch.

3. The charge pump device according to claim 2, characterized in that, The logic gates include AND gates and NAND gates.

4. The charge pump device according to claim 1, characterized in that, The slew rate control circuit includes: A current mirror has a main current path and a secondary current path, wherein a first end of the main current path and a first end of the secondary current path receive the power supply voltage. A current source, coupled to the second end of the main current path; and A capacitor, coupled to the second end of the current path, During the initial power-on phase of the power supply voltage, the second end of the current path generates the first reference voltage with the slew rate and supplies it to the comparator circuit.

5. The charge pump device according to claim 4, characterized in that, The capacitor is a variable capacitor.

6. The charge pump device according to claim 4, characterized in that, The current mirror includes: A first transistor provides the main current path, wherein a first terminal of the first transistor serves as the first terminal of the main current path, a second terminal of the first transistor serves as the second terminal of the main current path, and a control terminal of the first transistor is coupled to the second terminal of the first transistor; and A second transistor provides the slave current path, wherein a first terminal of the second transistor serves as the first terminal of the slave current path, a second terminal of the second transistor serves as the second terminal of the slave current path, and a control terminal of the second transistor is coupled to the control terminal of the first transistor.

7. The charge pump device according to claim 6, characterized in that, The second transistor is a variable transistor.

8. The charge pump device according to claim 1, characterized in that, The comparison circuit includes: A feedback circuit having an input terminal coupled to the output terminal of the charge pump circuit to receive the output voltage, wherein the feedback circuit generates a feedback voltage based on the output voltage; and A comparator determines whether to turn on the switch based on a first reference voltage, a second reference voltage, and a feedback voltage, wherein a first non-inverting input of the comparator is coupled to the slew rate control circuit to receive the first reference voltage, a second non-inverting input of the comparator receives the second reference voltage, an inverting input of the comparator is coupled to the output of the feedback circuit to receive the feedback voltage, and the output of the comparator is coupled to the control terminal of the switch.

9. The charge pump device according to claim 8, characterized in that, The feedback circuit includes: A first resistor having a first end coupled to the output of the charge pump circuit to receive the output voltage, wherein a second end of the first resistor is coupled to the inverting input of the comparator to provide the feedback voltage; and A second resistor has a first end coupled to the second end of the first resistor, wherein the second end of the second resistor is coupled to a third reference voltage.

10. The charge pump device according to claim 8, characterized in that, In response to the first reference voltage not reaching the second reference voltage, the comparator compares the first reference voltage with the feedback voltage; In response to the feedback voltage being less than the first reference voltage, the comparator turns on the switch; as well as In response to the feedback voltage being greater than the first reference voltage, the comparator turns off the switch.

11. The charge pump device according to claim 8, characterized in that, In response to the first reference voltage reaching the second reference voltage, the comparator compares the second reference voltage with the feedback voltage; In response to the feedback voltage being less than the second reference voltage, the comparator turns on the switch; as well as In response to the feedback voltage being greater than the second reference voltage, the comparator turns off the switch.

12. The charge pump device according to claim 1, characterized in that, The charge pump device further includes: An output capacitor is coupled to the output terminal of the charge pump circuit.

13. A method of operating a charge pump device, the charge pump device being used to generate an output voltage by performing pumping operation on a power supply voltage based on a clock signal triggering, characterized in that, The operation method includes: The clock signal is received by the first terminal of the switch of the charge pump device; The power supply voltage is received by the input terminal of the charge pump circuit of the charge pump device, wherein the clock terminal of the charge pump circuit is coupled to the second terminal of the switch; A first reference voltage with a rotational rate is generated by the rotational rate control circuit of the charge pump device; The first reference voltage and a second reference voltage having a fixed level are checked by the comparison circuit of the charge pump device, wherein the comparison circuit is coupled to the slew rate control circuit to receive the first reference voltage, the comparison circuit is coupled to the output terminal of the charge pump circuit to receive the output voltage, and the comparison circuit is coupled to the control terminal of the switch; In response to the first reference voltage not reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a first level relationship between the first reference voltage and the output voltage; In response to the first reference voltage reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a second level relationship between the second reference voltage and the output voltage; and When the switch is turned on, the charge pump circuit performs the pumping operation on the power supply voltage based on the clock signal at the clock terminal to generate the output voltage.

14. The operating method according to claim 13, characterized in that, The operation method further includes: A feedback voltage is generated by the feedback circuit of the comparator circuit based on the output voltage, wherein the input of the feedback circuit is coupled to the output of the charge pump circuit to receive the output voltage; and The comparator of the comparison circuit determines whether to turn on the switch based on the first reference voltage, the second reference voltage, and the feedback voltage. The first non-inverting input of the comparator is coupled to the slew rate control circuit to receive the first reference voltage, the second non-inverting input of the comparator receives the second reference voltage, the inverting input of the comparator is coupled to the output of the feedback circuit to receive the feedback voltage, and the output of the comparator is coupled to the control terminal of the switch.

15. The operating method according to claim 14, characterized in that, The operation method further includes: In response to the first reference voltage not reaching the second reference voltage, the comparator compares the first reference voltage with the feedback voltage; In response to the feedback voltage being less than the first reference voltage, the switch is turned on by the comparator; and In response to the feedback voltage being greater than the first reference voltage, the comparator turns off the switch.

16. The operating method according to claim 14, characterized in that, The operation method further includes: In response to the first reference voltage reaching the second reference voltage, the comparator compares the second reference voltage with the feedback voltage; In response to the feedback voltage being less than the second reference voltage, the switch is turned on by the comparator; and In response to the feedback voltage being greater than the second reference voltage, the comparator turns off the switch.

17. An application circuit, characterized in that, The application circuit includes: Multiple charge pump devices, wherein the input terminals of the multiple charge pump devices receive the same power supply voltage, and the multiple charge pump devices perform pumping operations on the power supply voltage based on the triggering of a clock signal to generate multiple output voltages with different slew rates.

18. The application circuit according to claim 17, characterized in that, Each of the plurality of charge pump devices includes: A switch having a first terminal that receives the clock signal; A charge pump circuit has a clock terminal coupled to a second terminal of the switch, wherein the input terminal of the charge pump circuit receives the power supply voltage, and the charge pump circuit generates the output voltage by performing the pumping operation on the power supply voltage based on the clock signal of the clock terminal when the switch is turned on; The slew rate control circuit generates a first reference voltage with slew rate; and A comparator circuit is coupled to the slew rate control circuit to receive the first reference voltage, coupled to the output of the charge pump circuit to receive the output voltage, and coupled to the control terminal of the switch, wherein the comparator circuit checks the first reference voltage against a second reference voltage having a fixed level. In response to the first reference voltage not reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a first level relationship between the first reference voltage and the output voltage; and In response to the first reference voltage reaching the second reference voltage, the comparator circuit determines whether to turn on the switch based on a second level relationship between the second reference voltage and the output voltage.

19. The application circuit according to claim 18, characterized in that, The slew rate control circuit includes: A current mirror has a main current path and a secondary current path, wherein a first end of the main current path and a first end of the secondary current path receive the power supply voltage. A current source, coupled to a second end of the main current path; and A capacitor, coupled to the second end of the current path, During the initial power-on phase of the power supply voltage, the second end of the current path generates the first reference voltage with the slew rate and supplies it to the comparator circuit.

20. The application circuit according to claim 18, characterized in that, The comparison circuit includes: A feedback circuit having an input terminal coupled to the output terminal of the charge pump circuit to receive the output voltage, wherein the feedback circuit generates a feedback voltage based on the output voltage; and A comparator determines whether to turn on the switch based on a first reference voltage, a second reference voltage, and a feedback voltage, wherein a first non-inverting input of the comparator is coupled to the slew rate control circuit to receive the first reference voltage, a second non-inverting input of the comparator receives the second reference voltage, an inverting input of the comparator is coupled to the output of the feedback circuit to receive the feedback voltage, and the output of the comparator is coupled to the control terminal of the switch.

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