Charge pump circuit for driving n-type switches

Abstract

The application is a charge pump circuit for driving N-type switch, characterized in that, comprising: a charge pump power circuit receiving a switch operating voltage (VSOP) and generating a charge pump output voltage (VCPOUT) higher than the switch operating voltage (VSOP); and a charge pump enable controller generating a charge pump enable signal (CP_EN); wherein the charge pump power circuit determines whether to work according to the charge pump enable signal (CP_EN) generated by the charge pump enable controller, and the charge pump output voltage (VCPOUT) is used to drive the N-type switch.

Description

Cross-reference to related applications

[0001] This application claims priority to Korean Patent Application No. 10-2025-0105107, filed on July 31, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to charge pump circuits. Specifically, this invention relates to a charge pump circuit that can be used to drive N-type switches and has low power consumption. Background Technology

[0003] N-type switches are used in a variety of applications. For example, they are widely used in chargers, overvoltage protection ICs (OVP ICs), and power ICs. Alternatively, power converters such as buck converters, boost converters, and buck-boost converters, which convert DC voltage to other DC voltage values, are another example of the use of N-type switches. A representative example of an N-type switch is, for instance, the N-channel field-effect transistor (N-FET).

[0004] To drive an N-type switch, a higher voltage than that at the source terminal must be applied to the gate terminal. For example, a voltage greater than the sum of the voltage at the node to which the source terminal is connected and the threshold voltage (Vth) required to turn the switch on must be applied to the gate terminal for the switch to conduct. In contrast to the case where the source terminal is connected to a reference voltage (GND), the source terminal of the switch is often connected to a node with a predetermined voltage or nodes with alternating voltages. For example, when the source terminal of the switch is connected to the positive terminal of the input power supply, a higher voltage than the input power supply voltage must be applied to the gate terminal, thus requiring a boost function to generate a voltage higher than the input power supply voltage. Charge pump circuits are widely used to drive N-type switches due to their superior boost function.

[0005] However, N-type switches need to be always operational, so the charge pump circuit used to drive the switch is typically always enabled. Therefore, there is a problem of continuous power consumption from the charge pump circuit. The power consumption of the charge pump circuit accounts for a large proportion of the overall power consumption of ICs using charge pump circuits, making it necessary to reduce its power consumption. Summary of the Invention

[0006] Technical issues

[0007] One of the technical challenges of this invention is to reduce the power consumption of the charge pump circuit used to drive N-type switches.

[0008] One of the technical challenges of this invention is to ensure that even if the switching operating voltage (VSOP) input to the charge pump power circuit changes, the first input voltage (VREF) of the comparator of the charge pump enable controller changes along with the switching operating voltage (VSOP), thereby reducing the power consumption of the charge pump power circuit.

[0009] One of the technical challenges of this invention is to reduce the power consumption of the charge pump power circuit by setting the offset voltage (VOFS) used when generating the charge pump enable signal (CP_EN) to be greater than the voltage drop (VL).

[0010] One of the technical challenges of this invention is to enable accurate calculations by using a current summator when generating the charge pump enable signal (CP_EN).

[0011] One of the technical challenges of this invention is to enable accurate calculations even when the input signal voltage is high by using a voltage divider when generating the charge pump enable signal (CP_EN).

[0012] One of the technical challenges of this invention is to enable the adjustment of the charge pump output voltage (VCPOUT) using the offset voltage (VOFS) used when generating the charge pump enable signal (CP_EN).

[0013] The technical issues of this invention are not limited to those described above, and various technical issues not mentioned herein may be included in this specification.

[0014] Technical solution

[0015] To achieve the above objectives, one aspect of the present invention is a charge pump circuit for driving an N-type switch, characterized in that it comprises: a charge pump power circuit that receives a switch operating voltage (VSOP) and generates a charge pump output voltage (VCPOUT) higher than the switch operating voltage (VSOP); and a charge pump enable controller that generates a charge pump enable signal (CP_EN); wherein the charge pump power circuit determines whether to operate based on the charge pump enable signal (CP_EN) generated by the charge pump enable controller, and the charge pump output voltage (VCPOUT) is used to drive the N-type switch.

[0016] As one embodiment, in the charge pump circuit, the charge pump enable controller includes a comparator that compares a first input voltage (VREF) of the comparator, generated based on the switching operating voltage (VSOP) input to the charge pump power circuit, with a second input voltage (V-) of the comparator, generated based on the charge pump feedback voltage (VCPFB) associated with the charge pump output voltage (VCPOUT), to generate the charge pump enable signal (CP_EN).

[0017] As one embodiment, in the charge pump circuit, the comparator first input voltage (VREF) can be generated based on the value obtained by subtracting the offset voltage (VOFS) from the sum of the switching operating voltage (VSOP) and the control power supply voltage (VDD).

[0018] As an example, in the charge pump circuit, when the second input voltage (V-) of the comparator becomes higher than or equal to the first input voltage (VREF) of the comparator, the charge pump enable signal (CP_EN) can be switched to a signal indicating disable, and the charge pump power circuit can stop working; when the second input voltage (V-) of the comparator becomes lower than or equal to the value obtained by subtracting the hysteresis voltage (VHYS) from the first input voltage (VREF) of the comparator, the charge pump enable signal (CP_EN) can be switched to a signal indicating enable, and the charge pump power circuit can restart working.

[0019] As one embodiment, in the charge pump circuit, the charge pump enable controller may further include a first-1 voltage summer (i.e., a first voltage summer), wherein the first-1 voltage summer may add the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) to the switching operating voltage (VSOP) to generate the comparator first input voltage (VREF).

[0020] As one embodiment, in the charge pump circuit, the charge pump enable controller may further include: a second-first voltage-to-current converter (i.e., a first voltage-to-current converter) that converts the switching operating voltage (VSOP) into a current signal; a second-second voltage-to-current converter (i.e., a second voltage-to-current converter) that converts the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) into a current signal; a second-first current summer (i.e., a first current summer) that adds the output current of the second-first voltage-to-current converter to the output current of the second-second voltage-to-current converter; and a second-first current-to-voltage converter (i.e., a first current-to-voltage converter) that converts the output current of the second-first current summer into a voltage signal to generate the first input voltage (VREF) of the comparator.

[0021] As an embodiment, in the charge pump circuit, the charge pump enable controller may further include: a 3-1 voltage divider (i.e., a first voltage divider) that converts the switching operating voltage (VSOP) into a value obtained by dividing by a predetermined value N; a 3-2 voltage divider (i.e., a second voltage divider) that converts the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) into a value obtained by dividing by N; a 3-1 voltage summer (i.e., a second voltage summer) that adds the output of the 3-1 voltage divider to the output of the 3-2 voltage divider to generate the first input voltage (VREF) of the comparator; and a 3-3 voltage divider (i.e., a third voltage divider) that converts the charge pump feedback voltage (VCPFB) into a value obtained by dividing by N to generate the second input voltage (V-) of the comparator.

[0022] As an embodiment, in the charge pump circuit, the charge pump enable controller may further include: a 4-1 voltage divider (i.e., the fourth voltage divider), which converts the switching operating voltage (VSOP) into a value obtained by dividing by a predetermined value N; a 4-1 voltage-to-current converter (i.e., the third voltage-to-current converter), which converts the output voltage of the 4-1 voltage divider into a current signal; a 4-2 voltage divider (i.e., the fifth voltage divider), which converts the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) into a value obtained by dividing by N; and a 4-2 voltage-to-current converter (i.e., the fourth voltage-to-current converter), which converts the output voltage of the 4-1 voltage divider into a current signal. The output voltage of the fourth-2 voltage divider is converted into a current signal; the fourth-1 current summer (i.e., the second current summer) adds the output current of the fourth-1 voltage-to-current converter to the output current of the fourth-2 voltage-to-current converter; the fourth-1 current-to-voltage converter (i.e., the second current-to-voltage converter) converts the output current of the fourth-1 current summer into a voltage signal to generate the first input voltage (VREF) of the comparator; and the fourth-3 voltage divider (i.e., the sixth voltage divider) converts the charge pump feedback voltage (VCPFB) into a value obtained by dividing by N to generate the second input voltage (V-) of the comparator.

[0023] As one embodiment, in the charge pump circuit, the offset voltage (VOFS) may be set to a value greater than the voltage drop (VL), which may include the voltage drop caused by the components used in the charge pump power circuit being non-ideal components.

[0024] As one embodiment, in the charge pump circuit, the charge pump output voltage (VCPOUT) can be adjusted by adjusting the offset voltage (VOFS).

[0025] As one embodiment, in the charge pump circuit, the switch operating voltage (VSOP) can be the voltage connected to the node of the drain terminal of the switch or the voltage connected to the node of the source terminal of the switch.

[0026] As one embodiment, in the charge pump circuit, the charge pump feedback voltage (VCPFB) can be the charge pump output voltage (VCPOUT).

[0027] As one embodiment, the charge pump circuit may further include: a driver that receives the charge pump output voltage (VCPOUT) and generates a switch drive voltage (VDRV) for driving the switch; wherein the charge pump feedback voltage (VCPFB) may be the switch drive voltage (VDRV).

[0028] Invention Effects

[0029] According to one embodiment, the power consumption of the charge pump circuit used to drive the N-type switch can be reduced.

[0030] According to one embodiment, even if the switching operating voltage (VSOP) input to the charge pump power circuit changes, the first input voltage (VREF) of the comparator of the charge pump enable controller changes along with the switching operating voltage (VSOP), thereby reducing the power consumption of the charge pump power circuit.

[0031] According to one embodiment, by setting the offset voltage (VOFS) used when generating the charge pump enable signal (CP_EN) to be greater than the voltage drop (VL), the power consumption of the charge pump power circuit can be reduced.

[0032] According to one embodiment, accurate calculations can be achieved by using a current summator when generating the charge pump enable signal (CP_EN).

[0033] According to one embodiment, accurate computation can be achieved even when the input signal voltage is high by using a voltage divider when generating the charge pump enable signal (CP_EN).

[0034] According to one embodiment, the charge pump output voltage (VCPOUT) can be adjusted using the offset voltage (VOFS) used when generating the charge pump enable signal (CP_EN).

[0035] The effects of the present invention are not limited to those described above, and many other effects not mentioned herein may be included in this specification. Attached Figure Description

[0036] Figure 1 This is an embodiment of a charge pump circuit.

[0037] Figure 2 This is another embodiment of a charge pump circuit.

[0038] Figure 3 This is an embodiment of a charge pump enable controller.

[0039] Figure 4 An exemplary method for generating the charge pump enable signal (CP_EN) is shown.

[0040] Figure 5 This is another embodiment of a charge pump enable controller.

[0041] Figure 6 This is yet another embodiment of a charge pump enable controller.

[0042] Figure 7 This is yet another embodiment of a charge pump enable controller. Detailed Implementation

[0043] Hereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary accompanying drawings. It should be noted that when affixing reference numerals to the constituent elements of each drawing, the same constituent elements will be labeled identically, even if they are shown in different drawings. Furthermore, in describing the present invention, detailed descriptions of relevant well-known structures or functions will be omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0044] Furthermore, when describing the constituent elements of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the constituent element from other constituent elements, and the nature, order, or sequence of the constituent elements are not limited by these terms. When a constituent element is described as being "connected," "combined," or "accessed" to another constituent element, it should be understood that the constituent element can be directly connected to or accessed to the other constituent element, but other constituent elements can also be "connected," "combined," or "accessed" between the constituent elements.

[0045] In this specification, "voltage" generally means the potential difference between two points. Unless otherwise specified, the reference point can be understood as the reference potential of the device (e.g., ground). Furthermore, in this specification, "voltage" may also be used to refer to the object providing such a potential difference, provided there is no risk of confusion in the context. For example, "input voltage" typically means the potential difference between the positive and negative terminals of an input power supply, but may also be used to refer to the input power supply itself, depending on the circumstances.

[0046] Figure 1 This is an embodiment of a charge pump circuit.

[0047] Figure 1 The charge pump circuit 100 illustrated herein can be used to drive an N-type switch SW1. A representative example of an N-type switch SW1 may be, for example, an N-channel field-effect transistor, but is not limited thereto. The N-type switch SW1 can be manufactured from a variety of structures and materials.

[0048] The N-type switch SW1 can be used in various application systems 10. Examples of application systems 10 include chargers, overvoltage protection ICs (OVP ICs), power ICs, power converters, etc., but are not limited to these. For ease of illustration, a charge pump circuit 100 is shown as an example. Figure 1 Application system 10 is shown in the accompanying diagram, but it should be understood that this does not mean that application system 10 is included in charge pump circuit 100. However, charge pump circuit 100 may be included in application system 10.

[0049] As one embodiment, the charge pump circuit 100 may include a charge pump enable controller 110, a charge pump power circuit 120, and a driver 130.

[0050] The charge pump power circuit 120 can receive the switching operating voltage (VSOP) and generate a charge pump output voltage (VCPOUT) that is higher than the switching operating voltage (VSOP). As one embodiment, the charge pump power circuit 120 can receive the switching operating voltage (VSOP) and the control power supply voltage (VDD) and generate a charge pump output voltage (VCPOUT) that is close to the sum of the switching operating voltage (VSOP) and the control power supply voltage (VDD). The charge pump output voltage (VCPOUT) can be applied directly to the gate terminal of switch SW1 to drive switch SW1, or it can be applied via driver 130.

[0051] As one embodiment, the charge pump power circuit 120 may be a switched-capacitor type power circuit that includes multiple switches and multiple capacitors, and generates the charge pump output voltage (VCPOUT) through the switching operation of the multiple switches. However, the charge pump power circuit 120 is not limited to this form. The charge pump power circuit 120 can use known technologies, therefore, this specification omits a detailed description of the charge pump power circuit 120 in order not to obscure the arguments.

[0052] The switching operating voltage (VSOP) can be the voltage of any of the nodes connected to the N-type switch SW1. As an example, the switching operating voltage (VSOP) can be the voltage of node N1 connected to the source terminal of switch SW1, or the voltage of node N2 connected to the drain terminal of switch SW1.

[0053] To turn on the N-type switch SW1, a voltage higher than the switching operating voltage (VSOP) needs to be applied to the gate terminal of switch SW1. For example, to turn on switch SW1, a voltage higher than the sum of the switching operating voltage (VSOP) and the threshold voltage (Vth) used to turn on switch SW1 needs to be applied to the gate terminal of switch SW1. For this purpose, a control power supply voltage (VDD) can be provided to the charge pump power circuit 120 along with the switching operating voltage (VSOP).

[0054] The control power supply can be a power source used to supply power to the components used in the control process. As one embodiment, a separate control power supply can be generated and supplied to the control components, having a voltage different from the main power supply of the application system 10. For example, in the case of a charger application, the charger can receive a voltage ranging from 3V to 19V from an external adapter and use this voltage to charge the battery. However, the control components cannot directly use a high voltage such as 19V; therefore, the charger can generate a separate control power supply with a voltage of 3.3V to 5V for the control components. However, the control power supply does not necessarily have to be a separate power source from the main power supply; depending on the circumstances, the main power supply can also be used as the control power supply.

[0055] As one embodiment, the charge pump power circuit 120 can determine whether to operate based on the charge pump enable signal (CP_EN) generated by the charge pump enable controller 110. As another embodiment, the charge pump power circuit 120 does not always remain enabled, but can operate only when the charge pump enable signal (CP_EN) indicates an enabled state, and stop operating when the charge pump enable signal (CP_EN) indicates a disabled state. According to this method, the power consumption of the charge pump power circuit 120 can be reduced.

[0056] As one embodiment, the charge pump power circuit 120 can receive a clock signal (CLK). Typically, the charge pump power circuit 120 includes a switch, and the clock signal (CLK) can be used to determine the switching time or switching period of the switch. Alternatively, the clock signal (CLK) can be used to determine the operating frequency of the control elements included within the charge pump power circuit 120.

[0057] The charge pump enable controller 110 can generate a charge pump enable signal (CP_EN). The charge pump enable controller 110 can receive a switching operating voltage (VSOP) and a charge pump feedback voltage (VCPFB), and generate the charge pump enable signal (CP_EN) based on these two voltages. Generating the charge pump enable signal (CP_EN) based on the switching operating voltage (VSOP) has the advantage of reducing the power consumption of the charge pump power circuit 120, which will be explained in detail below.

[0058] The charge pump feedback voltage (VCPFB) can be a voltage associated with the charge pump output voltage (VCPOUT). As one embodiment, the charge pump feedback voltage (VCPFB) can be the charge pump output voltage (VCPOUT) generated by the charge pump power circuit 120 or the switch drive voltage (VDRV) generated by the driver 130. The charge pump feedback voltage (VCPFB) can be provided to the charge pump enable controller 110 so that the charge pump enable controller 110 can grasp the state of the charge pump output voltage (VCPOUT) or the switch drive voltage (VDRV) and generate a charge pump enable signal (CP_EN).

[0059] As one embodiment, the charge pump enable controller 110 can receive a control power supply voltage (VDD). The components inside the charge pump enable controller 110 can operate using the control power supply.

[0060] Driver 130 can receive the charge pump output voltage (VCPOUT) generated by the charge pump power circuit 120 and generate a switch drive voltage (VDRV). The switch drive voltage (VDRV) can be a voltage applied to the gate terminal of switch SW1 to drive switch SW1. As an embodiment, driver 130 can be a buffer.

[0061] As one embodiment, driver 130 may receive a switch enable signal. Driver 130 may determine whether to operate based on the switch enable signal. For example, driver 130 may operate when the switch enable signal indicates an enabled state; driver 130 may stop operating when the switch enable signal indicates a disabled state.

[0062] Figure 2 This is another embodiment of a charge pump circuit. Figure 2 The charge pump circuit 200 shown in the example is with Figure 1 The difference in the exemplary charge pump circuit 100 shown is the absence of a driver 130. Driver 130 can be omitted if there is no problem in directly driving switch SW1 with the charge pump output voltage (VCPOUT) generated by the charge pump power circuit 120. In this case, the charge pump enable controller 110 can receive the charge pump output voltage (VCPOUT) generated by the charge pump power circuit 120 as the charge pump feedback voltage (VCPFB). Figure 2 The remaining structures illustrated herein can be applied by reference. Figure 1 The content of the explanation.

[0063] Figure 3This is an embodiment of a charge pump enable controller. Figure 3 The charge pump enable controller 110 illustrated in the example may include a comparator 111 and a first voltage summer 112.

[0064] Comparator 111 compares the first input voltage (VREF) and the second input voltage (V-) to generate a charge pump enable signal (CP_EN). As one embodiment, when the first input voltage (VREF) is higher than the second input voltage (V-), comparator 111 generates an "enable" charge pump enable signal (CP_EN); when the first input voltage (VREF) is lower than the second input voltage (V-), comparator 111 generates a "disable" charge pump enable signal (CP_EN). When the charge pump enable signal (CP_EN) indicates "enable," the charge pump power circuit 120 can operate; when the charge pump enable signal (CP_EN) indicates "disable," the charge pump power circuit 120 can stop operating.

[0065] The comparator's first input voltage (VREF) can be generated based on the switching operating voltage (VSOP) and the control supply voltage (VDD). As one embodiment, the comparator's first input voltage (VREF) can be generated based on the value obtained by subtracting the offset voltage (VOFS) from the sum of the switching operating voltage (VSOP) and the control supply voltage (VDD). As another embodiment, the comparator's first input voltage (VREF) can be the value obtained by subtracting the offset voltage (VOFS) from the sum of the switching operating voltage (VSOP) and the control supply voltage (VDD). As yet another embodiment, the offset voltage (VOFS) can have a value larger than the voltage drop (VL).

[0066] As one embodiment, voltage loss (VL) may include charge pump voltage loss (VLCP) caused by non-ideal components used in the charge pump power circuit 120. For example, even if the theoretically calculated charge pump output voltage (VCPOUT) is as shown in Equation 1 below, the actual charge pump output voltage (VCPOUT) may have a lower value than the theoretically expected value, as shown in Equation 2 below.

[0067] [Mathematical Expression 1]

[0068] VCPOUT = VSOP + VDD

[0069] [Mathematical Expression 2]

[0070] VCPOUT = VSOP + VDD – VLCP

[0071] Furthermore, as an embodiment, voltage loss (VL) may include drive circuit voltage loss (VLDRV) caused by the fact that the components used in driver 130 are not ideal components. For example, in the case where driver 130 is a buffer, even if the theoretically analyzed switching drive voltage (VDRV) is as shown in Equation 3 below, the actual switching drive voltage (VDRV) may have a lower value than the theoretically expected value due to the voltage loss (VLDRV) of the components inside driver 130, as shown in Equation 4 below.

[0072] [Mathematical Expression 3]

[0073] VDRV = VCPOUT

[0074] [Mathematical Expression 4]

[0075] VDRV = VCPOUT – VLDRV

[0076] As an example, voltage loss (VL) may include both charge pump voltage loss (VLCP) and drive circuit voltage loss (VLDRV).

[0077] By setting the offset voltage (VOFS) to be greater than the voltage drop (VL), the charge pump enable signal (CP_EN) can be prevented from remaining in the "enabled" state instead of entering the "disable" state, thus reducing the power loss of the charge pump power circuit. This will be discussed further below. Figure 4 To explain in more detail.

[0078] As one embodiment, the offset voltage (VOFS) can be used to regulate the charge pump output voltage (VCPOUT). This will be discussed further below. Figure 4 To explain in more detail.

[0079] The switching operating voltage (VSOP) received by the charge pump enable controller 110 can be applied to reference. Figure 1 The description includes details such as the switching operating voltage (VSOP). Figure 1 As shown, VN1 is the voltage at node N1 connected to the source terminal of switch SW1, or VN2 is the voltage at node N2 connected to the drain terminal of switch SW1. Thus, by varying the first input voltage (VREF) of the comparator with the switch operating voltage (VSOP), a charge pump enable signal (CP_EN) can be generated based on the switch operating voltage (VSOP).

[0080] The first voltage summer 112 (i.e., the first voltage summer) adds the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) to the switching operating voltage (VSOP) to generate the comparator's first input voltage (VREF). As one embodiment, the first voltage summer 112 can receive the voltage obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) and also receive the switching operating voltage (VSOP), and add the two received voltages to generate the comparator's first input voltage (VREF).

[0081] The comparator's second input voltage (V-) can be generated based on the charge pump feedback voltage (VCPFB). As one embodiment, the charge pump feedback voltage (VCPFB) can be used as is as the comparator's second input voltage (V-).

[0082] Figure 4 An exemplary method for generating the charge pump enable signal (CP_EN) is shown. Figure 4 The example shows the waveforms of the control power supply voltage (VDD) and the charge pump enable signal (CP_EN). Figure 4 An exemplary embodiment shows a charge pump enable controller 110, such as Figure 3 The configuration shown is as follows: that is, the first input voltage of the comparator VREF = VSOP + VDD - VOFS, and the second input voltage of the comparator (V-) = VCPFB.

[0083] If application system 10 starts operating, the control power supply voltage (VDD) can begin to rise to reach normal operation before time t0. When the charge pump enable controller 110 starts operating at time t0, the charge pump power circuit 120 has not yet generated a normal output voltage. Therefore, the comparator's second input voltage (V-), determined by the charge pump feedback voltage (VCPFB), is lower than the comparator's first input voltage (VREF), and the charge pump enable signal (CP_EN) can become an indication of "enable". With the charge pump enable signal (CP_EN) indicating "enable", the charge pump power circuit 120 can start operating, and the charge pump output voltage (VCPOUT) can begin to rise.

[0084] If the charge pump feedback voltage (VCPFB) equals the comparator's first input voltage (VREF) at time t0, the charge pump enable signal (CP_EN) can be switched to indicate "disable". Therefore, the charge pump power circuit 120 can stop operating, and the charge pump output voltage (VCPOUT) can begin to decrease.

[0085] If the charge pump feedback voltage (VCPFB) at time t2 is equal to the value obtained by subtracting the hysteresis voltage (VHYS) from the first input voltage (VREF) of the comparator, the charge pump enable signal (CP_EN) can be switched back to indicate "enable". Therefore, the charge pump power circuit 120 can restart, and the charge pump output voltage (VCPOUT) can start rising again.

[0086] Subsequently, in a similar manner, depending on the state of the charge pump enable signal (CP_EN), the charge pump power circuit 120 can repeatedly operate and stop operating, and the charge pump output voltage (VCPOUT) can repeatedly rise and fall within a predetermined voltage range. As an example, the maximum value of the operating range of the charge pump output voltage (VCPOUT) can be the first input voltage (VREF) of the comparator, and the minimum value can be the value obtained by subtracting the hysteresis voltage (VHYS) from the first input voltage (VREF) of the comparator.

[0087] Thus, when the second input voltage (V-) of the comparator is higher than the first input voltage (VREF) of the comparator (or when it increases while being equal), the charge pump enable signal (CP_EN) switches to a signal indicating "disable", and the operation of the charge pump power circuit 120 can be stopped; when the second input voltage (V-) of the comparator is lower than the value obtained by subtracting the hysteresis voltage (VHYS) from the first input voltage (VREF) of the comparator (or when it decreases while being equal), the charge pump enable signal (CP_EN) switches to a signal indicating "enable", and the operation of the charge pump power circuit 120 can be restarted.

[0088] Assuming the interval from time t3 to t5 is the normal state, the operating time of the charge pump power circuit 120 can be tcpe (= t5 - t4), the off-duty time of the charge pump power circuit 120 can be tcpd (= t4 - t3), and the operating cycle can be tcpe + tcpd. When the power consumption generated when the charge pump is always operating is set as Pcp, the power consumption (Pcp_new) in this embodiment can be reduced approximately as shown in the following mathematical formula 5. That is, the power loss of the charge pump power circuit 120 can be reduced according to the off-duty time (tcpd) of the charge pump power circuit 120.

[0089] [Mathematical Expression 5]

[0090] Pcp_new = Pcp * tcpe / (tcpe + tcpd)

[0091] Thus, according to this embodiment, the charge pump power circuit 120 does not operate all the time, but only operates within a portion of the operating cycle, thereby significantly reducing the power loss of the charge pump power circuit 120.

[0092] As an example, as previously described, the first input voltage (VREF) of the comparator can be formed as shown in the following mathematical formula 6.

[0093] [Mathematical Expression 6]

[0094] VREF = VSOP + VDD – VOFS

[0095] As shown in Equation 6, when the first input voltage (VREF) of the comparator varies with the switching operating voltage (VSOP), it has the following advantages: it reduces the impact of the operating state of switch SW1 and ensures the operation of the charge pump power circuit 120 during off periods, thereby reducing power consumption.

[0096] For example, the switching operating voltage (VSOP) can vary depending on the operating conditions of the application system 10. The switching operating voltage (VSOP) is the voltage at the node connected to the source or drain terminal of switch SW1, which is often connected to the input or output voltage of the application system 10. That is, the switching operating voltage (VSOP) can be either the input or output voltage of the application system 10. These voltages sometimes remain at a fixed value, but their values ​​often change. In this case, the switching operating voltage (VSOP) may also vary.

[0097] Even when the switching operating voltage (VSOP) varies while the comparator's first input voltage (VREF) remains constant, the comparator's first input voltage (VREF) is designed to have a relatively high value to ensure the normal conduction of switch SW1. In this case, if the switching operating voltage (VSOP) decreases, the charge pump output voltage (VCPOUT), whose magnitude is determined by the switching operating voltage (VSOP) and the control power supply voltage (VDD), also decreases. This may result in the charge pump output voltage (VCPOUT) failing to rise as high as the comparator's first input voltage (VREF). In this situation, the charge pump enable signal (CP_EN) remains in an "enabled" state, causing the charge pump power circuit 120 to always operate, potentially leading to a situation where the power loss of the charge pump power circuit 120 is not reduced.

[0098] According to this embodiment, the first input voltage (VREF) of the comparator can vary with the switching operating voltage (VSOP). In this case, when the switching operating voltage (VSOP) changes, the first input voltage (VREF) of the comparator also changes, thus appropriately ensuring the off-period of the charge pump power circuit 120. For example, if the switching operating voltage (VSOP) increases, the charge pump output voltage (VCPOUT) increases, and the first input voltage (VREF) of the comparator also increases, thus ensuring the disabled period of the charge pump power circuit 120 while ensuring sufficient conduction of the switch SW1. Furthermore, if the switching operating voltage (VSOP) decreases, the charge pump output voltage (VCPOUT) decreases, and the first input voltage (VREF) of the comparator also decreases, thus ensuring the disabled period of the charge pump power circuit 120 while preventing unnecessary increases in the charge pump output voltage (VCPOUT). Therefore, despite the variation in the switching operating voltage (VSOP), the power consumption of the charge pump power circuit 120 can be effectively reduced.

[0099] That is, by comparing the first input voltage (VREF) of the comparator, which is generated based on the switching operating voltage (VSOP) input to the charge pump power circuit 120, with the second input voltage (V-) of the comparator, which is generated based on the charge pump feedback voltage (VCPFB) associated with the charge pump output voltage (VCPOUT), to generate the charge pump enable signal (CP_EN), the power consumption of the charge pump power circuit 120 can be effectively reduced.

[0100] As an example, the offset voltage (VOFS) can be set to be greater than the voltage drop (VL). As mentioned earlier, the maximum value of the charge pump output voltage (VCPOUT) can be calculated based on the voltage drop (VL) caused by the actual components as shown in Equation 7, and the first input voltage of the comparator (VREF) can be set as shown in Equation 6 above.

[0101] [Mathematical Expression 7]

[0102] VCPOUT = VSOP + VDD – VL

[0103] [Mathematical Expression 6]

[0104] VREF = VSOP + VDD – VOFS

[0105] When the charge pump output voltage (VCPOUT) is used as the second input voltage (V-) of the comparator, if the offset voltage (VOFS) is set to the same value as the voltage drop (VL), the first input voltage (VREF) of the comparator and the second input voltage (V-) of the comparator will only be the same when the charge pump output voltage (VCPOUT) reaches its maximum value, thus stopping the charge pump power circuit 120. With this design, the charge pump output voltage (VCPOUT) may fail to reach its maximum value due to various variables. In this case, the charge pump power circuit 120 may continue to operate without any power reduction effect. Alternatively, even if the charge pump power circuit 120 stops operating, the period of operation may be short, and the power reduction effect may be minimal. To prevent this problem, the offset voltage (VOFS) is preferably set to be greater than the voltage drop (VL). In this case, the period of operation stoppage can be sufficiently ensured, thus providing the advantage of reduced power consumption.

[0106] As one embodiment, the offset voltage (VOFS) can be used to adjust the charge pump output voltage (VCPOUT). As previously mentioned, the maximum value of the operating range of the charge pump output voltage (VCPOUT) can be the first input voltage of the comparator (VREF), and the minimum value can be the value obtained by subtracting the hysteresis voltage (VHYS) from the first input voltage of the comparator (VREF). That is, the range of the charge pump output voltage (VCPOUT) can be determined based on the first input voltage of the comparator (VREF), and the first input voltage of the comparator (VREF) can be adjusted by the offset voltage (VOFS) as shown in Equation 6. Therefore, by adjusting the offset voltage (VOFS), the range of the charge pump output voltage (VCPOUT) can be adjusted. For example, if the offset voltage (VOFS) is increased, the charge pump output voltage (VCPOUT) can be decreased; conversely, if the offset voltage (VOFS) is decreased, the charge pump output voltage (VCPOUT) can be increased.

[0107] A hysteresis voltage (VHYS) can be used to prevent the charge pump power circuit 120 from frequently turning on and off. For example, without the hysteresis voltage (VHYS), if the charge pump feedback voltage (VCPFB) is higher than or equal to the comparator's first input voltage (VREF), the charge pump power circuit 120 stops operating, and after a short time delay, the charge pump feedback voltage (VCPFB) decreases. If the charge pump feedback voltage (VCPFB) decreases, the charge pump power circuit 120 restarts, and after a short time delay, the charge pump feedback voltage (VCPFB) rises again, operating in this manner. That is, the problem of frequent crossings between the charge pump feedback voltage (VCPFB) and the comparator's first input voltage (VREF) and repeated frequent on / off switching of the charge pump power circuit 120 can occur, while using the hysteresis voltage (VHYS) can prevent this phenomenon.

[0108] As one embodiment, the hysteresis voltage (VHYS) can be implemented internally within comparator 111. As another embodiment, the hysteresis voltage (VHYS) can be implemented in either the first input voltage (VREF) or the second input voltage (V-) of the comparator. The hysteresis voltage (VHYS) can be implemented using known techniques, therefore its detailed description is omitted here.

[0109] Figure 5 This is another embodiment of a charge pump enable controller.

[0110] Reference Figure 5 Based on the comparator 511, the charge pump enable controller 510 may also include a second-first voltage-to-current converter 514 (i.e., a first voltage-to-current converter), a second-second voltage-to-current converter 516 (i.e., a second voltage-to-current converter), a second-first current summer 512 (i.e., a first current summer), and a second-first current-to-voltage converter 517 (i.e., a first current-to-voltage converter).

[0111] The comparator 511 can be used for... Figure 3 The description of comparator 111 is omitted here, as it is redundant.

[0112] The voltage-to-current converter 514, number 2-1, can convert the switching operating voltage (VSOP) into a current signal.

[0113] The voltage-to-current converter 516 can convert the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) into a current signal.

[0114] The second-first current summer 512 can add the output current of the second-first voltage-to-current converter 514 to the output current of the second-second voltage-to-current converter 516.

[0115] The 2-1 current-to-voltage converter 517 can convert the output current of the 2-1 current summer 512 into the first input voltage (VREF) of the comparator.

[0116] Thus, the comparator's first input voltage (VREF), generated by summing the value obtained from subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) and the switching operating voltage (VSOP), can also be generated using voltage-to-current converters 514 and 516 and a current summer 512. When the comparator's first input voltage (VREF) is generated using a voltage signal, errors caused by voltage drops in various components may be included. Conversely, when the comparator's first input voltage (VREF) is generated using a current signal, a current mirror circuit or similar device can be used, resulting in the advantage of achieving more accurate calculations.

[0117] Figure 6 This is yet another embodiment of a charge pump enable controller.

[0118] Reference Figure 6 The charge pump enable controller 610, based on the comparator 611, may also include a third-first voltage divider 613 (i.e., the first voltage divider), a third-second voltage divider 615 (i.e., the second voltage divider), a third-first voltage summer 612 (i.e., the second voltage summer), and a third-third voltage divider 618 (i.e., the third voltage divider).

[0119] Comparator 611 can be used for Figure 3 The content described by comparator 111 is omitted here for brevity.

[0120] The voltage divider 613 (3-1) can convert the switching operating voltage (VSOP) into the value obtained by dividing by a predetermined value N.

[0121] The voltage divider 615 (3-2) can convert the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) into the value obtained by dividing by N.

[0122] The third-first voltage summer 612 can add the output of the third-first voltage divider 613 to the output of the third-second voltage divider 615 to generate the first input voltage (VREF) of the comparator.

[0123] The third-3 voltage divider 618 can convert the charge pump feedback voltage (VCPFB) into the value obtained by dividing by N to generate the second input voltage (V-) of the comparator.

[0124] Thus, the charge pump enable controller 610 can also be implemented using a voltage divider. According to this embodiment, it is more effective when the switching operating voltage (VSOP) or charge pump feedback voltage (VCPFB) is too high for general components to handle.

[0125] Figure 7 This is yet another embodiment of a charge pump enable controller.

[0126] Reference Figure 7 Based on comparator 711, charge pump enable controller 710 may further include a fourth voltage divider 713 (i.e., the fourth voltage divider), a fourth voltage-to-current converter 714 (i.e., the third voltage-to-current converter), a fourth voltage divider 715 (i.e., the fifth voltage divider), a fourth voltage-to-current converter 716 (i.e., the fourth voltage-to-current converter), a fourth current summer 712 (i.e., the second current summer), a fourth current-to-voltage converter 717 (i.e., the second current-to-voltage converter), and a fourth voltage divider 718 (i.e., the sixth voltage divider).

[0127] The comparator 711 can be used for... Figure 3 The content described by comparator 111 is omitted here for brevity.

[0128] The voltage divider 713 (4-1) can convert the switching operating voltage (VSOP) into the value obtained by dividing by a predetermined value N.

[0129] The voltage-to-current converter 714 of section 4-1 can convert the output voltage of voltage divider 713 of section 4-1 into a current signal.

[0130] The voltage divider 715 (4-2) can convert the value obtained by subtracting the offset voltage (VOFS) from the control power supply voltage (VDD) into the value obtained by dividing by N.

[0131] The 4-2 voltage-to-current converter 716 can convert the output voltage of the 4-2 voltage divider 715 into a current signal.

[0132] The 4-1 current summer 712 can add the output current of the 4-1 voltage-to-current converter 714 to the output current of the 4-2 voltage-to-current converter 716.

[0133] The 4-1 current-to-voltage converter 717 can convert the output current of the 4-1 current summer 712 into a voltage signal to generate the first input voltage (VREF) of the comparator.

[0134] The 4-3 voltage divider 718 can convert the charge pump feedback voltage (VCPFB) into the value obtained by dividing by N to generate the comparator's second input voltage (V-).

[0135] Thus, the charge pump enable controller 710 can be implemented using a voltage divider and a current summer. In this case, it is effective not only when the switching operating voltage (VSOP) or charge pump feedback voltage (VCPFB) is too high for general components to handle, but also has the advantage of enabling more accurate calculations by utilizing current signals.

[0136] As described above, according to this embodiment, by comparing the first input voltage (VREF) of the comparator generated based on the switching operating voltage input to the charge pump power circuit 120 with the second input voltage (V-) of the comparator generated based on the charge pump feedback voltage (VCPFB) associated with the charge pump output voltage (VCPOUT) to generate a charge pump enable signal (CP_EN), the power consumption of the charge pump power circuit 120 can be effectively reduced.

[0137] The terms "comprising," "constituting," or "having" used above, unless specifically stated otherwise, mean that the corresponding constituent elements may be included. Therefore, they should be interpreted as not excluding other constituent elements, but rather potentially including them. Unless otherwise defined, all terms, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms commonly used, such as those defined in dictionaries, should be interpreted as having the meaning consistent with their meaning in the relevant technical context, and are not construed as having an idealized or overly formalized meaning unless explicitly defined herein.

[0138] The above description is merely illustrative of the technical concept of the present invention. Those skilled in the art can make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in this invention are not intended to limit the scope of the invention but rather to illustrate its technical concept. The scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of this invention should be interpreted by the following claims, and all technical concepts falling within its equivalent scope should be interpreted as being included within the scope of the claims of this invention.

[0139] [Symbol Explanation] 110: Charge Pump Enable Controller 120: Charge Pump Power Circuit 130: Driver CLK: Clock signal for charge pump CP_EN: Charge pump enable signal SW1: N-type switch VCPFB: Charge Pump Feedback Voltage VCPOUT: Charge pump output voltage VDD: Control power supply voltage VDRV: Switching drive voltage VHYS: Hysteresis voltage VL: Voltage loss VLCP: Charge Pump Voltage Loss VLDRV: Voltage loss in the drive circuit VOFS: Offset Voltage VREF: First input voltage of the comparator VSOP: Switching Operating Voltage V-: Second input voltage of the comparator

Claims

1. A charge pump circuit for driving an N-type switch, characterized in that, include: A charge pump power circuit that receives a switch operating voltage and generates a charge pump output voltage that is higher than the switch operating voltage; as well as A charge pump enable controller that generates a charge pump enable signal; The charge pump power circuit determines whether to operate based on the charge pump enable signal generated by the charge pump enable controller. The output voltage of the charge pump is used to drive the N-type switch.

2. The charge pump circuit according to claim 1, characterized in that, The charge pump enable controller includes a comparator. The comparator compares a first input voltage of the comparator, generated based on the switching operating voltage input to the charge pump power circuit, with a second input voltage of the comparator, generated based on the charge pump feedback voltage associated with the charge pump output voltage, to generate the charge pump enable signal.

3. The charge pump circuit according to claim 2, characterized in that, The first input voltage of the comparator is generated based on the value obtained by subtracting the offset voltage from the sum of the switching operating voltage and the control power supply voltage.

4. The charge pump circuit according to claim 2, characterized in that, When the second input voltage of the comparator becomes higher than or equal to the first input voltage of the comparator, the charge pump enable signal switches to a signal indicating disabling, and the charge pump power circuit stops working; when the second input voltage of the comparator becomes lower than or equal to the value obtained by subtracting the hysteresis voltage from the first input voltage of the comparator, the charge pump enable signal switches to a signal indicating enabling, and the charge pump power circuit restarts working.

5. The charge pump circuit according to claim 3, characterized in that, The charge pump enable controller also includes a first voltage summer. The first voltage summer adds the value obtained by subtracting the offset voltage from the control power supply voltage to the switch operating voltage to generate the first input voltage of the comparator.

6. The charge pump circuit according to claim 3, characterized in that, The charge pump enable controller also includes: A first voltage-to-current converter converts the switching operating voltage into a current signal; The second voltage-to-current converter converts the value obtained by subtracting the offset voltage from the control power supply voltage into a current signal; A first current summer adds the output current of the first voltage-to-current converter to the output current of the second voltage-to-current converter; and A first current-to-voltage converter converts the output current of the first current summer into a voltage signal to generate the first input voltage of the comparator.

7. The charge pump circuit according to claim 3, characterized in that, The charge pump enable controller also includes: A first voltage divider converts the switching operating voltage into a value obtained by dividing by a predetermined value N; The second voltage divider converts the value obtained by subtracting the offset voltage from the control power supply voltage into the value obtained by dividing by N; A second voltage summer adds the output of the first voltage divider to the output of the second voltage divider to generate the first input voltage of the comparator; and A third voltage divider converts the charge pump feedback voltage into a value divided by N to generate the second input voltage of the comparator.

8. The charge pump circuit according to claim 3, characterized in that, The charge pump enable controller also includes: The fourth voltage divider converts the switching operating voltage into a value obtained by dividing by a predetermined value N; The third voltage-to-current converter converts the output voltage of the fourth voltage divider into a current signal; The fifth voltage divider converts the value obtained by subtracting the offset voltage from the control power supply voltage into the value obtained by dividing by N; The fourth voltage-to-current converter converts the output voltage of the fifth voltage divider into a current signal; The second current summer adds the output current of the third voltage-to-current converter to the output current of the fourth voltage-to-current converter; A second current-to-voltage converter converts the output current of the second current summer into a voltage signal to generate the first input voltage of the comparator; and The sixth voltage divider converts the charge pump feedback voltage into a value divided by N to generate the second input voltage of the comparator.

9. The charge pump circuit according to claim 3, characterized in that, The offset voltage is set to a value greater than the voltage drop. The voltage loss includes the voltage drop caused by the fact that the components used in the charge pump power circuit are not ideal components.

10. The charge pump circuit according to claim 3, characterized in that, Adjust the offset voltage to adjust the output voltage of the charge pump.

11. The charge pump circuit according to claim 2, characterized in that, The switch operating voltage is the voltage at the node connected to the drain terminal of the N-type switch or the voltage at the node connected to the source terminal of the N-type switch.

12. The charge pump circuit according to claim 2, characterized in that, The charge pump feedback voltage is the charge pump output voltage.

13. The charge pump circuit according to claim 2, characterized in that, The charge pump circuit further includes a driver that receives the output voltage of the charge pump and generates a switching drive voltage for driving the N-type switch. The charge pump feedback voltage is the switch drive voltage.

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