Controller circuit, dc / dc converter, and electronic device

Abstract

To provide a controller IC that reduces the design burden.SOLUTION: A mode determination circuit 210 determines a first mode and a second mode: (i) in the first mode, a feedback controller 220 generates a first control signal CTRL1 for controlling the states of a first transistor M1 and a second transistor M2 and a second control signal CTRL2 for controlling the states of a third transistor M3 and a fourth transistor M4 so that a feedback voltage VFB occurring at a feedback pin FB approaches a first reference voltage; and (ii) in the second mode, the feedback controller 220 generates a third control signal CTRL3, for controlling the states of the third transistor M3 and the fourth transistor M4 so that the feedback voltage VFB approaches a second target voltage.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a controller circuit for a DC / DC converter. [Background technology]

[0002] Buck converters are used to generate voltages lower than the power supply voltage. Buck converters convert an input voltage V IN Any voltage level in the range below the output voltage V OUT A buck converter can generate an input voltage V IN As this increases, switching losses increase and efficiency decreases.

[0003] Hybrid DC / DC converters with topologies other than the step-down converter, three-level converters, and series capacitor DC / DC converters have been proposed. IN In contrast to a DC / DC converter that generates a switching signal with an amplitude proportional to the input voltage V and stores energy in an inductor, a hybrid DC / DC converter uses a capacitor to store the input voltage V IN Amplitude V is 1 / 2 of IN The hybrid DC / DC converter generates a switching signal with an input voltage of V IN In high-voltage applications, the efficiency can be improved compared to conventional step-down converters. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-013283 A

[0005] [overview] The output voltage V that a hybrid DC / DC converter can generate OUT The range of V IN / 2 or less. Therefore, system designers had to select either a step-down converter or a hybrid converter based on the relationship between the input voltage and output voltage used in the system, and then design the circuit. Specifically, they had to select a controller IC (Integrated Circuit) for the selected type of converter, and then design a printed circuit board and peripheral circuits that were compatible with that controller IC.

[0006] If there were a controller IC that could be used universally, regardless of the relationship between the input voltage and the output voltage, it would greatly reduce the burden on designers.

[0007] It is within this context that the present disclosure has been made.

[0008] One embodiment of the present disclosure relates to a controller circuit for controlling a DC / DC converter.The controller circuit includes a mode determination circuit for determining whether the first mode or the second mode is selected; a power supply pin to which an input voltage should be supplied in a first application corresponding to the first mode and a second application corresponding to the second mode; a first switching pin to which a first end of the flying capacitor should be connected in the first application; an intermediate voltage pin to which the intermediate capacitor is connected in the first application and to which the input voltage should be supplied in the second application; a second switching pin to which a second end of the flying capacitor should be connected in the first application and the second application; a power ground pin to be grounded in the first application and the second application; a first transistor connected between the power supply pin and the first switching pin; a second transistor connected between the first switching pin and the intermediate voltage pin; a third transistor connected between the intermediate voltage pin and the second switching pin; a feedback pin to receive a feedback voltage corresponding to the input voltage; and a feedback controller that (i) generates, in a first mode, a first control signal instructing states of the first transistor and the second transistor and a second control signal instructing states of the third transistor and the fourth transistor such that a feedback voltage generated at the feedback pin approaches a first reference voltage, and (ii) generates, in a second mode, a third control signal instructing states of the third transistor and the fourth transistor such that the feedback voltage approaches the second reference voltage. a first driver that, in a first mode, generates a first gate voltage on the gate of the first transistor and generates a second gate voltage on the gate of the second transistor based on a first control signal; and a second driver that (i) in the first mode, generates a third gate voltage on the gate of the third transistor and generates a fourth gate voltage on the gate of the fourth transistor based on the second control signal, and (ii) in the second mode, generates the third gate voltage on the gate of the third transistor and generates the fourth gate voltage on the gate of the fourth transistor based on the third control signal.

[0009] Any combination of the above components, or mutual substitution of components or expressions between methods, devices, systems, etc., are also effective as aspects of the present invention or the present disclosure. Furthermore, the description in this section (Means for Solving the Problems) does not explain all essential features of the present invention, and therefore, subcombinations of the described features may also constitute the present invention. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a circuit diagram of a DC / DC converter according to a first application including a controller circuit according to a first embodiment. [Diagram 2] FIG. 2 is a circuit diagram showing an example of the configuration of the mode determination circuit. [Diagram 3] FIG. 3 is a circuit diagram showing an example of the configuration of the mode determination circuit. [Figure 4] FIG. 4 is a circuit diagram showing an example of the configuration of the mode determination circuit. [Diagram 5] FIG. 5 is a circuit diagram showing an example of the configuration of the mode determination circuit. [Figure 6] FIG. 6 is a diagram illustrating the operation of the DC / DC converter according to the first application. [Figure 7] FIG. 7 is a circuit diagram of a DC / DC converter according to a second application including the controller circuit according to the first embodiment. [Figure 8] FIG. 8 is a circuit diagram of a DC / DC converter according to a first application including a controller circuit according to the second embodiment. [Figure 9] FIG. 9 is a circuit diagram of a DC / DC converter according to a second application including the controller circuit according to the second embodiment. [Figure 10] FIG. 10 is a circuit diagram of a modification of the DC / DC converter of FIG. [Figure 11] FIG. 11 is a diagram illustrating an example of an electronic device including a DC / DC converter.

[0011] [Detailed Description] (Overview of the embodiment) A summary of some exemplary embodiments of the present disclosure will be described. This summary is intended to provide a simplified overview of some concepts of one or more embodiments for a basic understanding of the embodiments as a prelude to the detailed description that follows, and is not intended to limit the scope of the invention or disclosure. This summary is not intended to be an exhaustive overview of all possible embodiments, nor is it intended to identify key elements of all embodiments or to delineate the scope of some or all aspects. For convenience, the term "one embodiment" may be used to refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed in this specification.

[0012] A controller circuit of a DC / DC converter according to one embodiment includes a mode determination circuit for determining whether a first mode or a second mode is selected; a power supply pin to which an input voltage should be supplied in a first application corresponding to the first mode and a second application corresponding to the second mode; a first switching pin to which a first end of a flying capacitor should be connected in the first application; an intermediate voltage pin to which an intermediate capacitor is connected in the first application and to which an input voltage should be supplied in the second application; a second switching pin to which a second end of the flying capacitor should be connected in the first application and the second application; a power ground pin to be grounded in the first application and the second application; a first transistor connected between the power supply pin and the first switching pin; a second transistor connected between the first switching pin and the intermediate voltage pin; a third transistor connected between the intermediate voltage pin and the second switching pin; and in a second application, a feedback pin for receiving a feedback voltage according to an output voltage of the DC / DC converter; a feedback controller for (i) generating, in a first mode, a first control signal for instructing states of the first transistor and the second transistor and a second control signal for instructing states of the third transistor and the fourth transistor so that a feedback voltage generated at the feedback pin approaches a first reference voltage, and (ii) generating, in a second mode, a third control signal for instructing states of the third transistor and the fourth transistor so that the feedback voltage approaches the second reference voltage; a first driver for generating a first gate voltage on a gate of the first transistor and a second gate voltage on a gate of the second transistor based on the first control signal, in the first mode; and (i) generating a third gate voltage on a gate of the third transistor and a fourth gate voltage on a gate of the fourth transistor based on the second control signal, in the first mode,and a second driver that generates a fourth gate voltage on the gate of the fourth transistor.

[0013] By connecting the components of a hybrid converter to the controller circuit and setting the controller circuit mode to the first mode, it is possible to generate an output voltage lower than half the input voltage with high efficiency. By connecting the components of a step-down converter to the controller circuit and setting the controller circuit mode to the second mode, it is possible to generate an output voltage lower than the input voltage with high efficiency. Because the controller circuit is a common component for both the hybrid converter and the step-down converter, it can be used universally, regardless of the relationship between the input voltage and output voltage.

[0014] In one embodiment, the controller circuit may further include a charge pump circuit configured to generate and supply a boosted voltage higher than the input voltage to the first driver in the second mode. The feedback controller may generate a fourth control signal to supply to the first driver in the second mode such that the first transistor and the second transistor are turned on.

[0015] In one embodiment, in the second application, the intermediate voltage pin may be left unconnected.

[0016] In one embodiment, the feedback controller may generate a fourth control signal to provide to the first driver in the second mode such that the first transistor and the second transistor are off.

[0017] In one embodiment, the controller circuitry may further comprise a mode setting pin, and the mode determination circuitry may determine the mode based on the electrical state of the mode setting pin.

[0018] In one embodiment, the controller circuit may be capable of recording information specifying the mode internally in a non-volatile manner.

[0019] In one embodiment, the mode determination circuit may determine the mode depending on the input voltage.

[0020] In one embodiment, the controller circuit may be monolithically integrated on a single semiconductor substrate. "Monolithic integration" includes cases where all of the circuit components are formed on a semiconductor substrate, and cases where the main components of the circuit are monolithically integrated, and some resistors, capacitors, etc. may be provided outside the semiconductor substrate for adjusting the circuit constants. By integrating the circuit on a single chip, the circuit area can be reduced and the characteristics of the circuit elements can be kept uniform.

[0021] A DC / DC converter according to one embodiment includes any of the controller circuits described above, and a peripheral circuit having a topology of either a hybrid converter or a step-down converter.

[0022] An electronic device according to an embodiment includes the above-mentioned DC / DC converter.

[0023] (Embodiment) Hereinafter, the present disclosure will be described with reference to the drawings based on preferred embodiments. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and duplicated descriptions will be omitted as appropriate. In addition, the embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0024] In this specification, "a state in which component A is connected to component B" includes not only a case in which component A and component B are directly physically connected to each other, but also a case in which component A and component B are indirectly connected to each other via other components that do not substantially affect the electrical connection state between them or that do not impair the function or effect achieved by their combination.

[0025] Similarly, "a state in which component C is provided between components A and B" includes not only the case in which components A and C, or components B and C, are directly connected to each other, but also the case in which they are indirectly connected to each other via other components that do not substantially affect the electrical connection between them or that do not impair the functions or effects achieved by their combination.

[0026] Furthermore, "signal A (voltage, current) corresponds to signal B (voltage, current)" means that signal A has a correlation with signal B, specifically meaning (i) when signal A is signal B, (ii) when signal A is proportional to signal B, (iii) when signal A is obtained by level-shifting signal B, (iv) when signal A is obtained by amplifying signal B, (v) when signal A is obtained by inverting signal B, (vi) or any combination thereof. Those skilled in the art will understand that the scope of "corresponding to" is determined according to the types and applications of signals A and B.

[0027] (Embodiment 1) FIG. 1 is a circuit diagram of a DC / DC converter 100A according to a first application, which includes a controller circuit 200 according to the first embodiment. The controller circuit 200 is an IC (Integrated Circuit) that supports both a hybrid converter and a step-down converter. In the first application, the controller circuit 200 configures a DC / DC converter 100A together with a peripheral circuit 110A having a hybrid converter topology, as shown in FIG. 1. In addition, as shown in FIG. 7, which will be described later, the controller circuit 200 can also configure a DC / DC converter 100B together with a peripheral circuit 110B having a step-down (Buck) converter topology in a second application. The DC / DC converters 100A and 100B are collectively referred to as the DC / DC converter 100, and the peripheral circuits 110A and 110B are collectively referred to as the peripheral circuit 110. The DC / DC converter 100 receives an input voltage V of an input line 102, and outputs a voltage V of the input line 102. IN The output voltage V OUT on output line 104.

[0028] In this specification, the subscript A will be used in relation to the first application, and the subscript B will be used in relation to the second application.

[0029] In the first application shown in FIG. 1, the DC / DC converter 100A is a hybrid converter. The peripheral circuit 110A having the topology of a hybrid converter is mainly composed of an input capacitor C IN , flying capacitor C FLY , intermediate capacitor C MID , output capacitor C OUT , inductor L. Input capacitor C IN and the output capacitor C OUT are smoothing capacitors connected to the input line 102 and the output line 104, respectively.

[0030] Sense resistor R SENSE is the coil current I flowing through the inductor L L The sense resistor R SENSE is the coil current I L This voltage drop is proportional to the current sense signal V CS is fed back to the controller circuit 200.

[0031] Feedback resistor R FB1 ,R FB2 are connected in series between the output line 104 and ground to form a voltage divider circuit 112. The voltage divider circuit 112 divides the output voltage V OUT is divided, and the output voltage V OUT The feedback voltage V FB is generated.

[0032] The controller circuit 200 is set to a first mode (also called a hybrid mode) in a platform used together with a peripheral circuit 110A having a hybrid converter topology. In the first mode, the controller circuit 200 controls the first transistor M1 to the fourth transistor M4 to regulate the input voltage VIN and outputs a predetermined target level V OUT(REF) The output voltage V OUT In the hybrid converter, V OUT(REF) <V IN Output voltage V in the range of ×1 / 2 OUT The level of

[0033] Next, the configuration of the controller circuit 200 will be described.

[0034] The controller circuit 200 includes a first transistor M1 to a fourth transistor M4, a mode determination circuit 210, a feedback controller 220, a first driver 230, a second driver 240, and an internal regulator 250. The internal regulator 250 receives a power supply voltage V REG Generates the power supply voltage V REG is supplied to the internal circuit blocks of the controller circuit 200 and is output via the power supply voltage pin VREG. VREG is connected. Power supply voltage V REG is supplied to the drive voltage pin VDRV.

[0035] The controller circuit 200 is capable of switching between a first mode (hybrid mode) corresponding to a first application, i.e., a hybrid converter, and a second mode (also called single mode) corresponding to a second application, i.e., a step-down converter. The mode determination circuit 210 determines whether the first mode or the second mode is set. For example, the controller circuit 200 includes a mode setting pin MODE, and the mode can be set based on the electrical state of this mode setting pin MODE. The method of setting the mode is not particularly limited, but the following is an example.

[0036] A two-value mode control signal, high or low, may be input to the mode setting pin MODE from outside the controller circuit 200. In this case, the mode determination circuit 210 can determine the mode according to the level of the mode setting pin MODE.

[0037] 2 is a circuit diagram showing an example configuration (210A) of the mode determination circuit 210. Either an external pull-up resistor Rext1 or a pull-down resistor Rext2 is connected to the mode setting pin MODE. When the pull-up resistor Rext1 is connected, the mode control signal generated at the mode setting pin MODE is high (VDD), and when the pull-down resistor Rext2 is connected, the mode control signal generated at the mode setting pin MODE is low (0V). The mode determination circuit 210 can be configured, for example, with a voltage comparator 212, and compares the voltage of the mode setting pin MODE with a predetermined threshold voltage V TH 2. When the mode determination circuit 210 is configured with, for example, a voltage comparator 212, the mode setting pin MODE may be directly connected to high (VDD) without passing through the pull-up resistor Rext1 shown in FIG. 2. When the mode determination circuit 210 is configured with, for example, a voltage comparator 212, the mode setting pin MODE may be directly connected to low (0 V) without passing through the pull-down resistor Rext2 shown in FIG. 2.

[0038] As a modification of FIG. 2, the controller circuit 200 may have a built-in pull-down resistor. In this case, when the pull-up resistor Rext1 is not connected to the outside, the voltage of the mode setting pin MODE is low. Conversely, when the pull-up resistor Rext1 is connected to the outside, the voltage of the mode setting pin MODE is high (V DD )

[0039] As another modification of FIG. 2, the controller circuit 200 may have a built-in pull-up resistor. In this case, when the pull-down resistor Rext2 is not connected to the outside, the voltage of the mode setting pin MODE is high. Conversely, when the pull-down resistor Rext2 is connected to the outside, the voltage of the mode setting pin MODE is high (V DD )

[0040] 3 is a circuit diagram showing another example (210B) of the mode determination circuit 210. A mode control signal MODE that is high or low is input to the mode setting pin MODE from the external circuit 130. For example, the external circuit 130 is a microcontroller, and this mode control signal MODE is supplied from a GPIO (General Purpose Input / Output).

[0041] FIG. 4 is a circuit diagram showing another example (210C) of the mode determination circuit 210. An external resistor Rpg is connected to the mode setting pin MODE. When the first mode is to be set, a component higher (lower) than a predetermined threshold is used for the resistor Rpg, and when the second mode is to be set, a component lower (higher) than the predetermined threshold is used. The mode determination circuit 210C includes a resistance value detection circuit 214 and a comparator 216. The resistance value detection circuit 214 detects the resistance value of the resistor Rpg and generates a detection signal Rdet indicating the resistance value. The comparator 216 compares the detection signal Rdet with a threshold value to determine the mode.

[0042] 5 is a circuit diagram showing another example (210D) of the mode determination circuit 210. The mode setting pin MODE is connected to the input voltage V IN Set voltage V proportional to IN For example, the set voltage V IN The voltage V′ at the mode setting pin MODE is generated by an external resistor divider circuit 132. The resistor divider circuit 132 always has the same voltage division ratio regardless of the mode to be set. IN ' is the threshold voltage V THand determine the mode.

[0043] According to the configuration of Figure 5, the input voltage V IN This configuration allows the output voltage V OUT This is effective when the target level of the output voltage V OUT When used for applications where the input voltage is V = 5V, IN The mode determination circuit 210D may be configured to determine the first mode when the input voltage VIN is higher than 10V, and to determine the second mode when the input voltage VIN is lower than 10V.

[0044] The resistive voltage divider circuit 132 may be integrated into the controller circuit 200. In that case, the mode setting pin MODE can also serve as the power supply pin VDD, making it possible to reduce the number of pins.

[0045] Alternatively, the controller circuit 200 may 2 It may also be provided with a serial interface circuit such as an Inter IC (C) interface, a Serial Peripheral Interface (SPI), or a Universal Asynchronous Receiver Transmitter (UART). In this case, an external circuit may transmit data specifying a mode to the serial interface circuit, and the mode determination circuit 210 may determine the mode based on the received data.

[0046] The information regarding the mode may be recorded in a nonvolatile manner inside the controller circuit 200. For example, the controller circuit 200 may include a nonvolatile memory such as an OTP (One Time Programmable) memory, an MTP (Multiple Time Programmable) memory, a flash memory, or a fuse, and the information regarding the mode may be written in the nonvolatile memory.

[0047] Alternatively, the controller circuit 200 may be provided with a mode setting pad to which a bonding wire can be connected, so that the mode can be set according to the destination of the bonding wire connected to this mode setting pad.

[0048] Returning to FIG. 1, the configuration of the controller circuit 200 will be described. The power supply pin VDD is connected to an input voltage V IN is provided. The first transistor M1 is connected between a power supply pin VDD and a first switching pin LX1. The second transistor M2 is connected between the first switching pin LX1 and an intermediate voltage pin VMID. The third transistor M3 is connected between the intermediate voltage pin VMID and a second switching pin LX2. The fourth transistor M4 is connected between the second switching pin LX2 and a power ground pin PGND.

[0049] In this embodiment, the first transistor M1 to the fourth transistor M4 are NMOS transistors, and a bootstrap circuit is used to drive them. In association with the bootstrap circuit, the controller circuit 200 includes bootstrap pins BOOT1 to BOOT3. Inside the controller circuit 200, a power supply voltage V REG are supplied to the bootstrap pins BOOT1 to BOOT3 via rectifying elements (not shown).

[0050] A bootstrap capacitor C is connected between the bootstrap pin BOOT1 and the LX1 pin. BOOT1 A bootstrap capacitor C is connected between the bootstrap pin BOOT2 and the intermediate voltage pin VMID. BOOT2 The intermediate voltage pin VMID is connected to the intermediate capacitor C MID A bootstrap capacitor C is connected between the bootstrap pin BOOT3 and the LX2 pin. BOOT3 is connected.

[0051] A Zener diode ZD1 is connected between the BOOT1 pin and the BOOT2 pin. A Zener diode ZD2 is connected between the BOOT2 pin and the BOOT3 pin. A Zener diode ZD3 is connected between the BOOT3 pin and the drive voltage pin VDRV.

[0052] In the first mode, the feedback pin FB is connected to the voltage divider circuit 112 and is connected to the output voltage V OUT Feedback voltage V according to FB Receive.

[0053] The controller circuit 200 has a sense resistor R SENSE The voltage drop that occurs in the current detection signal V CS ) will be received.

[0054] In a first application, the feedback controller 220 is set to a first mode by the mode decision circuit 210. In the first mode, the feedback controller 220 controls the feedback signal V FB is the first reference voltage V REF1 A first control signal CTRL1 that instructs the first transistor M1 and the second transistor M2 to be on or off, and a second control signal CTRL2 that instructs the third transistor M3 and the fourth transistor M4 to be on or off are generated so that the output voltage V approaches . The first control signal CTRL1 is supplied to the first driver 230, and the second control signal CTRL2 is supplied to the second driver 240. OUT is the target voltage V OUT(REF1) =V REF1 ×(R FB1 +R FB2 ) / R FB2 is stabilized to. Feedback resistor R FB1 ,R FB2 Resistance value and first reference voltage V REF1 The voltage level of V OUT(REF1) <V IN / 2 It can be designed in the range of

[0055] The control method and configuration of the feedback controller 220 in the first mode are not particularly limited, and may be any known technology or technology that can be used in the future. In the case of the current mode feedback controller 220, the feedback signal V FB In addition, the current sense signal V CS is used to generate the first control signal CTRL1 and the second control signal CTRL2. In the case of the voltage mode control method, the current detection signal V CS may be used for overcurrent protection, etc.

[0056] The first driver 230 generates a first driving voltage at the gate HG1 of the first transistor M1 and generates a second driving voltage at the gate LG1 of the second transistor M2 based on the first control signal CTRL1. The first driver 230 includes drivers Dr1 and Dr2. The upper power supply node of the driver Dr1 is connected to the bootstrap pin BOOT1, and the lower power supply node is connected to the first switching pin LX1. The upper power supply node of the driver Dr2 is connected to the bootstrap pin BOOT2, and the lower power supply node is connected to the intermediate voltage pin VMID.

[0057] The second driver 240 generates a third driving voltage at the gate HG2 of the third transistor M3 and generates a fourth driving voltage at the gate LG2 of the fourth transistor M4 based on the second control signal CTRL2. The second driver 240 includes drivers Dr3 and Dr4. The upper power supply node of the driver Dr3 is connected to the bootstrap pin BOOT3, and the lower power supply node is connected to the second switching pin LX2. The upper power supply node of the driver Dr4 is connected to the driving voltage pin VDRV, and the lower power supply node is grounded via the power ground pin PGND.

[0058] Through feedback control by the feedback controller 220, the DC / DC converter 100A alternates between a first state φ1 in which the first transistor M1 and the third transistor M3 are on and the second transistor M2 and the fourth transistor M4 are off, and a second state φ2 in which the second transistor M2 and the fourth transistor M4 are on and the first transistor M1 and the third transistor M3 are off. Note that a dead time in which all transistors are off can be inserted between the first state φ1 and the second state φ2.

[0059] 6 is a diagram illustrating the operation of the DC / DC converter 100A according to the first application. The left side of FIG. 6 shows a first state φ1, and the right side shows a second state φ2. In the first state φ1, the coil current I L is the sum of the current from the first transistor M1 and the current from the third transistor M3, and the current flows substantially equally in half to the first transistor M1 and the third transistor M3. MID is discharged, and the flying capacitor C FLY is charged.

[0060] In the second state φ2, the flying capacitor C FLY and the intermediate capacitor C MID The voltages of the two are connected together, and the voltages of the two are V IN The fourth transistor M4 has a coil current I L and two capacitors C FLY and C MID A current flows that is the sum of the currents associated with the charge transfer between the electrodes.

[0061] By repeatedly switching between the first state φ1 and the second state φ2, in the steady state, the flying capacitor C FLY and the intermediate capacitor C MID The voltage across the IN The control by the feedback controller 220 is basically the same as that of a step-down converter, and the output voltage V OUT Target level V OUT(REF1)The time ratio of the first state φ1 and the second state φ2 may be adjusted so as to approach φ1 while keeping the switching frequency constant (PWM control). Alternatively, the time of one of the first state φ1 and the second state φ2 may be fixed, and the length of the other may be changed (PFM control). Alternatively, the feedback controller 220 may switch between the first state φ1 and the second state φ2 by ripple control.

[0062] FIG. 7 is a circuit diagram of a DC / DC converter 100B according to a second application including the controller circuit 200 according to the first embodiment.

[0063] In a second application shown in FIG. 7, the DC / DC converter 100B is a step-down converter. The peripheral circuit 110B having a step-down converter topology mainly includes an input capacitor C IN , output capacitor C OUT , inductor L. Input capacitor C IN and the output capacitor C OUT are smoothing capacitors connected to the input line 102 and the output line 104, respectively.

[0064] The power supply pin VDD and the intermediate voltage pin VMID are connected to the input voltage V IN The bootstrap pins BOOT1 and BOOT2 and the first switching pin LX1 of the controller circuit 200 are set to non-connection (NC).

[0065] In the second application, the feedback controller 220 is set to a second mode by the mode decision circuit 210. In the second mode, the feedback controller 220 controls the feedback signal V FB is the second reference voltage V REF2 The third control signal CTRL3 is supplied to the second driver 240. REF2 is the first reference voltage V REF1may be the same as or different from.

[0066] The control method and configuration of the feedback controller 220 in the second mode are not particularly limited, and may be any known technology or technology that can be used in the future. In the case of the current mode feedback controller 220, the feedback signal V FB In addition, the current sense signal V CS is used to generate the second control signal CTRL2. In the case of the voltage mode control method, the current detection signal V CS may be used for overcurrent protection, etc.

[0067] The second driver 240 generates a third driving voltage to the gate HG2 of the third transistor M3 and generates a fourth driving voltage to the gate LG2 of the fourth transistor M4 based on the third control signal CTRL3.

[0068] In the controller circuit 200 according to the present embodiment, in the second application, since no bootstrap capacitors are connected to the bootstrap pins BOOT1 and BOOT2, the first transistor M1 and the second transistor M2 cannot be turned on by the drivers Dr1 and Dr2 of the first driver 230.

[0069] Therefore, the feedback controller 220 may supply the fourth control signal CTRL4 to the first driver 230 so that the first transistor M1 and the second transistor M2 are fixed to be off. This can reduce switching loss in the first driver 230 when the controller circuit 200 operates in the second mode. In addition, EMI (Electromagnetic Interference) can be suppressed.

[0070] Alternatively, the feedback controller 220 may supply the fourth control signal CTRL4, which is the same as the first control signal CTRL1 in the first mode, to the first driver 230. The fourth control signal CTRL4 may be in a high impedance state (undefined), and therefore the states of the first transistor M1 and the second transistor M2 may be undefined.

[0071] The output voltage V OUT is the second target voltage V OUT(REF2) =V REF2 ×(R FB1 +R FB2 ) / R FB2 is stabilized to. Feedback resistor R FB1 ,R FB2 and the second reference voltage V REF2 The voltage level of V OUT(REF2) <V IN It can be designed in the range of

[0072] The above is the configuration of the controller circuit 200 and the DC / DC converters 100A, 100B that use it. According to this controller circuit 200, by selecting the first mode, it can be used in a platform that requires a hybrid converter, and by selecting the second mode, it can be used in a platform that requires a step-down converter.

[0073] The hybrid converter is connected to the capacitor C FLY ,C MID The voltage at V IN / 2, it has the advantage of being resistant to input voltage fluctuations. IN On the other hand, a step-down converter is less tolerant to input voltage fluctuations than a hybrid converter, but has no restrictions on the output voltage range.

[0074] Designers who design several platforms select an appropriate DC / DC converter type for each platform, but whichever type is selected, can use the same controller circuit 200, reducing the design burden compared to when a different controller circuit is selected for each platform. Also, procurement costs can be reduced compared to when a different controller circuit is purchased for each platform.

[0075] (Embodiment 2) 8 is a circuit diagram of a DC / DC converter 100Aa according to a first application including a controller circuit 200a according to embodiment 2. A peripheral circuit 110A having a hybrid converter topology is connected to the controller circuit 200a.

[0076] The controller circuit 200a includes a charge pump circuit 260 in addition to the controller circuit 200 in FIG. 1. The charge pump circuit 260 is switchable between an enabled state and a disabled state. The mode determination circuit 210 enables the charge pump circuit 260 in the second mode. In the enabled state, the charge pump circuit 260 is IN A boost voltage higher than V CP The boost voltage V generated by the charge pump circuit 260 CP is supplied to the upper power supply nodes of the drivers Dr1 and Dr2. In the first application shown in FIG. 8, the charge pump circuit 260 is disabled, and the boost voltage V CP is not generated.

[0077] In the first application, the controller circuit 200a operates similarly to the controller circuit 200 of the first embodiment.

[0078] FIG. 9 is a circuit diagram of a DC / DC converter 100Ba according to a second application including a controller circuit 200a according to the second embodiment.

[0079] In the second application, the peripheral circuit 110Ba has a step-down converter topology, but the wiring is different from that of the peripheral circuit 110B in Fig. 7. Specifically, in the peripheral circuit 110B in Fig. 8, the power supply pin VDD and the intermediate voltage pin VMID are connected by wiring outside the controller circuit 200a, but this wiring is omitted in the peripheral circuit 110Ba in Fig. 9.

[0080] In the second application, the charge pump circuit 260 is enabled and supplies the boosted voltage V CP In the second mode, the feedback controller 220 generates the fourth control signal CTRL4 such that the first transistor M1 and the second transistor M2 are turned on.

[0081] The drivers Dr1 and Dr2 receive the boosted voltage V CP By utilizing this, the drivers Dr1 and Dr2 can turn on the first transistor M1 and the second transistor M2.

[0082] That is, in the second application of the second embodiment, the first transistor M1 and the second transistor M2 are fixed in the on state, so that the input voltage V IN is supplied.

[0083] Fig. 10 is a circuit diagram of a DC / DC converter 100Bb according to a modified example. The peripheral circuit 110Bb includes wiring that connects the power supply pin VDD and the intermediate voltage pin VMID of the controller circuit 200a. The rest is the same as in Fig. 9. In this modified example, when operating in the second mode, the power supply pin VDD and the intermediate voltage pin VMID are electrically connected via two paths: the transistors M1 and M2 inside the controller circuit 200a and a wiring outside the controller circuit 200a.

[0084] (Modification) The above-described embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each processing step. Such modifications will be described below.

[0085] In the embodiment, a bootstrap circuit is used to drive the first transistor M1 to the third transistor M3, which are NMOS transistors, but the present disclosure is not limited thereto. For example, a charge pump circuit may be built into the controller circuit 200, and the charge pump circuit may be used to generate a high-level voltage of the drive voltage to be applied to the gates of the first transistor M1 to the third transistor M3. In this case, a bootstrap pin or the like can be omitted from the controller circuit 200.

[0086] Further, some or all of the first transistor M1 to the third transistor M3 may be configured as PMOS transistors, in which case no bootstrap circuit is required.

[0087] (Application) 11 is a diagram showing an example of an electronic device 700 including a DC / DC converter 100. The electronic device 700 includes a power supply circuit 720 and at least one internal circuit 710. The power supply circuit 720 receives an input voltage V IN It is stepped down to the output voltage V OUT and supplies it to the internal circuit 710.

[0088] The electronic device 700 is, for example, a server. Alternatively, the electronic device 700 may be an in-vehicle device. Alternatively, the electronic device 700 may be an industrial device, an office automation device, or a consumer device such as an audio device.

[0089] The embodiments are merely examples, and it will be understood by those skilled in the art that there are various modifications in the combination of each component and each treatment process, and that such modifications are also included in the present disclosure.

[0090] (Additional Note) One aspect of the technology disclosed in this specification can be understood as follows.

[0091] (Item 1) A controller circuit for a DC / DC converter, comprising: a mode determination circuit for determining whether the first mode or the second mode is selected; a power supply pin to which an input voltage should be supplied in a first application corresponding to the first mode and in a second application corresponding to the second mode; a first switching pin to which a first end of a flying capacitor is to be connected in the first application; an intermediate voltage pin to which an intermediate capacitor is connected in the first application and to which the input voltage should be supplied in the second application; a second switching pin to which a second end of the flying capacitor is to be connected in the first application and the second application; a power ground pin to be grounded in the first application and the second application; a first transistor connected between the power supply pin and the first switching pin; a second transistor connected between the first switching pin and the intermediate voltage pin; a third transistor connected between the intermediate voltage pin and the second switching pin; a fourth transistor connected between the second switching pin and the power ground pin; a feedback pin for receiving a feedback voltage corresponding to an output voltage of the DC / DC converter in the first application and the second application; (i) in the first mode, a feedback controller generates a first control signal for instructing a state of the first transistor and the second transistor and a second control signal for instructing a state of the third transistor and the fourth transistor such that the feedback voltage generated at the feedback pin approaches a first reference voltage, and (ii) in the second mode, a third control signal for instructing a state of the third transistor and the fourth transistor such that the feedback voltage approaches a second reference voltage. (i) a first driver that generates a first gate voltage on a gate of the first transistor and a second gate voltage on a gate of the second transistor based on the first control signal in the first mode; (i) a second driver that generates a third gate voltage on a gate of the third transistor and a fourth gate voltage on a gate of the fourth transistor based on the second control signal in the first mode, and (ii) a second driver that generates a third gate voltage on a gate of the third transistor and a fourth gate voltage on a gate of the fourth transistor based on the third control signal in the second mode; A controller circuit comprising:

[0092] (Item 2) a charge pump circuit configured to generate a boosted voltage higher than the input voltage and supply the boosted voltage to the first driver in the second mode; 2. The controller circuit of claim 1, wherein the feedback controller generates a fourth control signal to supply to the first driver so that the first transistor and the second transistor are turned on in the second mode.

[0093] (Item 3) 3. The controller circuit of claim 2, wherein in the second application, the intermediate voltage pin is unconnected.

[0094] (Item 4) 2. The controller circuit of claim 1, wherein the feedback controller generates a fourth control signal to supply to the first driver such that, in the second mode, the first transistor and the second transistor are off.

[0095] (Item 5) Further comprising a mode setting pin; 5. The controller circuit of any one of items 1 to 4, wherein the mode determination circuit determines the mode based on an electrical state of the mode setting pin.

[0096] (Item 6) 5. The controller circuit of any one of items 1 to 4, capable of recording information specifying the mode therein in a non-volatile manner.

[0097] (Item 7) 5. The controller circuit of any one of items 1 to 4, wherein the mode determination circuit determines a mode depending on the input voltage.

[0098] (Item 8) 8. The controller circuit according to any one of items 1 to 7, which is monolithically integrated on a single semiconductor substrate.

[0099] (Item 9) A controller circuit according to any one of items 1 to 8; A peripheral circuit having either a hybrid converter or a buck converter topology; A DC / DC converter comprising:

[0100] (Item 10) 10. An electronic device comprising the DC / DC converter according to item 9. [Explanation of symbols]

[0101] 100 DC / DC Converter 102 input lines 104 Output Line M1 First transistor M2 Second transistor M3 Third transistor M4 4th transistor 110 Peripheral circuits 200 Controller Circuit VDD Power supply pin LX1 First switching pin VMID Mid Voltage Pin LX2 Second switching pin ISNSP, ISNSN Current sense pins FB Feedback pin AGND Ground pin C FLY Flying Capacitor L Inductor C MID Intermediate Capacitor C OUT Output Capacitor C BOOT Bootstrap Capacitor 210 Mode determination circuit 220 Feedback Controller 230 1st Driver 240 2nd Driver

Claims

1. A controller circuit for a DC / DC converter, comprising: a mode determination circuit for determining whether the first mode or the second mode is selected; a power supply pin to which an input voltage should be supplied in a first application corresponding to the first mode and a second application corresponding to the second mode; a first switching pin to which a first end of a flying capacitor is to be connected in the first application; an intermediate voltage pin to which an intermediate capacitor is connected in the first application and to which the input voltage should be supplied in the second application; a second switching pin to which a second end of the flying capacitor is to be connected in the first application and the second application; a power ground pin to be grounded in the first application and the second application; a first transistor connected between the power supply pin and the first switching pin; a second transistor connected between the first switching pin and the intermediate voltage pin; a third transistor connected between the intermediate voltage pin and the second switching pin; a fourth transistor connected between the second switching pin and the power ground pin; a feedback pin for receiving a feedback voltage corresponding to an output voltage of the DC / DC converter in the first application and the second application; (i) generating, in the first mode, a first control signal for instructing a state of the first transistor and the second transistor and a second control signal for instructing a state of the third transistor and the fourth transistor such that the feedback voltage generated at the feedback pin approaches a first reference voltage; and (ii) generating, in the second mode, a third control signal for instructing a state of the third transistor and the fourth transistor such that the feedback voltage approaches a second reference voltage. (i) a first driver that generates a first gate voltage on a gate of the first transistor and a second gate voltage on a gate of the second transistor based on the first control signal in the first mode; (i) a second driver that, in the first mode, generates a third gate voltage on a gate of the third transistor and generates a fourth gate voltage on a gate of the fourth transistor based on the second control signal, and (ii) in the second mode, generates a third gate voltage on a gate of the third transistor and generates a fourth gate voltage on a gate of the fourth transistor based on the third control signal; A controller circuit comprising:

2. a charge pump circuit configured to generate a boosted voltage higher than the input voltage and supply the boosted voltage to the first driver in the second mode; 2. The controller circuit of claim 1, wherein the feedback controller generates a fourth control signal to provide to the first driver in the second mode such that the first transistor and the second transistor are on.

3. 3. The controller circuit of claim 2, wherein in the second application, the intermediate voltage pin is left unconnected.

4. 2. The controller circuit of claim 1, wherein the feedback controller generates a fourth control signal to provide to the first driver in the second mode such that the first transistor and the second transistor are off.

5. Further comprising a mode setting pin; 5. The controller circuit according to claim 1, wherein the mode determination circuit determines the mode based on an electrical state of the mode setting pin.

6. 5. The controller circuit according to claim 1, wherein information for designating said mode is recordable therein in a non-volatile manner.

7. The controller circuit according to claim 1 , wherein the mode determination circuit determines the mode depending on the input voltage.

8. 5. The controller circuit according to claim 1, which is monolithically integrated on a single semiconductor substrate.

9. A controller circuit according to any one of claims 1 to 4; A peripheral circuit having either a hybrid converter or a buck converter topology; A DC / DC converter comprising:

10. An electronic device comprising the DC / DC converter according to claim 9.

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