Voltage stabilizing circuit suitable for high-voltage power supply management chip and chip

Abstract

The invention relates to the technical field of integrated circuit design, high-voltage power supply management chips and the like, and provides a voltage stabilizing circuit suitable for a high-voltage power supply management chip and the high-voltage power supply management chip. The circuit comprises an error amplifier, an N-channel MOS tube M1 and a voltage setting feedback network. The error amplifier outputs a control signal to the grid electrode of the M1 by comparing a reference voltage with a feedback voltage; the drain electrode of the M1 is connected with input high voltage VIN, and the source electrode is grounded through a feedback network to form a negative feedback structure. The voltage stabilizing circuit provided by the invention is simple in structure, high in stability and fast in response, can solve the problems of complex loop gain and difficult compensation, realizes the simplification of a loop structure, improves the phase margin of a circuit system, enhances the stability and load transient response, can be integrated in a high-voltage power supply management chip, and has a wide application prospect. And a stable low-voltage power supply is provided for high-voltage applications such as industry and automotive electronics.

Description

Technical Field

[0001] This invention relates to the fields of integrated circuit design and high-voltage power management chips, and particularly to a voltage regulator circuit and a high-voltage power management chip suitable for high-voltage power management chips. Background Technology

[0002] A high-voltage power management chip circuit is a complete circuit system consisting of a dedicated high-voltage power management chip as its core, along with necessary external components (such as inductors, capacitors, resistors, and power MOSFETs). Its core task is to efficiently, reliably, and accurately manage and convert high input voltages to provide the necessary stable power to other electronic components or subsystems. In the integrated circuit field, the high voltage in a high-voltage power management chip circuit refers to a voltage much higher than the operating voltage of the chip's internal core logic circuit (e.g., 3.3V, 5V). In a high-voltage power management chip circuit, after the high voltage is converted to a low voltage (e.g., 5V), it is processed by a voltage regulator circuit to obtain a stable low voltage to power the chip's internal control circuit. Currently, conventional voltage regulator circuits typically use PMOS as the power MOSFET to achieve a lower input-output voltage difference. However, the introduction of PMOS introduces a gain stage into the control loop, making enable loop compensation difficult, resulting in complex loop compensation, insufficient system stability, and inadequate load transient response.

[0003] In summary, existing high-voltage power management chip circuits suffer from technical problems such as difficulty in enabling loop compensation, complexity of loop compensation, insufficient system stability, and insufficient load transient response. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this invention provides a voltage regulation circuit and a high-voltage power management chip suitable for high-voltage power management chips, achieving simpler loop compensation, better stability, and better load transient response.

[0005] In a first aspect, the present invention provides a voltage regulation circuit suitable for high-voltage power management chips, comprising: an error amplifier, wherein the non-inverting input terminal of the error amplifier is electrically connected to the output terminal of a reference voltage source to receive a reference voltage; the error amplifier compares the reference voltage with a feedback voltage obtained from the output voltage and outputs a control signal for adjusting the conduction state of an N-channel MOSFET M1; the N-channel MOSFET M1 is electrically connected to the output terminal of the error amplifier and to the input voltage VIN, and is used to receive the control signal and drive the conduction state according to the received control signal; the error amplifier, the N-channel MOSFET M1, and the voltage setting feedback network form a negative feedback structure; the source of the N-channel MOSFET M1 is electrically connected to the voltage setting terminal of the voltage setting feedback network; the voltage setting feedback network is used to set and generate the output voltage at the voltage setting terminal, and to acquire the output voltage to obtain the feedback voltage, and to perform frequency compensation on the feedback loop of the negative feedback structure; the feedback voltage is connected to the inverting input terminal of the error amplifier through the signal feedback terminal of the voltage setting feedback network.

[0006] Secondly, the present invention provides a high-voltage power management chip, wherein the high-voltage power management chip uses the above-mentioned voltage regulation circuit.

[0007] Compared with the prior art, the beneficial effects of this invention are as follows: This invention provides a voltage regulator circuit and a high-voltage power management chip suitable for high-voltage power management chips. The circuit includes: an error amplifier, the non-inverting input of which is electrically connected to the output of a reference voltage source to receive a reference voltage; the error amplifier compares the reference voltage with a feedback voltage obtained from the output voltage and outputs a control signal for adjusting the conduction state of an N-channel MOSFET M1; an N-channel MOSFET M1, electrically connected to the output of the error amplifier and to the input voltage VIN, for receiving the control signal and driving its conduction state according to the received control signal; the error amplifier, the N-channel MOSFET M1, and the voltage setting feedback network form a negative feedback structure; the source of the N-channel MOSFET M1 is electrically connected to the voltage setting terminal of the voltage setting feedback network; the voltage setting feedback network is used to set and generate the output voltage at the voltage setting terminal, acquire the output voltage to obtain the feedback voltage, and perform frequency compensation on the feedback loop of the negative feedback structure; the feedback voltage is connected to the inverting input of the error amplifier through the signal feedback terminal of the voltage setting feedback network. The voltage regulator circuit provided by this invention has a simple structure, high stability, and fast response. It can solve the problems of complex loop gain and difficult compensation, simplify the loop structure, improve the phase margin of the circuit system, enhance stability and load transient response, and can be integrated into high-voltage power management chips to provide stable low-voltage power for high-voltage applications such as industrial and automotive electronics. Attached Figure Description

[0008] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. Some specific embodiments of the invention will be described in detail below with reference to the accompanying drawings in an exemplary and non-limiting manner. The same reference numerals in the drawings designate the same or similar parts or components. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of a voltage regulation circuit applicable to a high-voltage power management chip according to an embodiment of the present invention; Figure 2 This is a schematic diagram of another circuit structure for a voltage regulation circuit applicable to a high-voltage power management chip according to an embodiment of the present invention. Detailed Implementation

[0009] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0010] This invention provides a voltage regulator circuit and a high-voltage power management chip suitable for high-voltage power management chips, wherein the high-voltage power management chip uses the voltage regulator circuit.

[0011] See Figures 1-2 The voltage regulation circuit suitable for high-voltage power management chips includes: An error amplifier is provided, wherein the non-inverting input terminal of the error amplifier is electrically connected to the output terminal of a reference voltage source to receive a reference voltage. The error amplifier compares the reference voltage with a feedback voltage obtained from the output voltage and outputs a control signal for adjusting the conduction state of the N-channel MOSFET M1. The N-channel MOSFET M1 is electrically connected to the output terminal of the error amplifier and to the input voltage VIN, and is used to receive the control signal and drive the conduction state according to the received control signal. The error amplifier, the N-channel MOSFET M1, and the voltage setting feedback network constitute a negative feedback structure. The source of the N-channel MOSFET M1 is electrically connected to the voltage setting terminal of the voltage setting feedback network. The voltage setting feedback network generates the output voltage at the voltage setting terminal, acquires the output voltage to obtain the feedback voltage, and performs frequency compensation on the feedback loop of the negative feedback structure. The feedback voltage is connected to the inverting input terminal of the error amplifier through the signal feedback terminal of the voltage setting feedback network.

[0012] In this embodiment, by using an N-channel MOSFET M1 as the power transistor, electrically connecting it to the input voltage VIN, and electrically connecting its source to the voltage setting terminal of the voltage setting feedback network to set the output voltage, the problem of introducing a gain stage in the control loop, making loop compensation difficult, and causing loop compensation complexity caused by using a PMOS as the power MOSFET can be solved. This simplifies the loop structure and reduces the number of loop gain stages. The error amplifier, the N-channel MOSFET M1, and the voltage setting feedback network form a negative feedback structure. The voltage setting feedback network performs frequency compensation on the feedback loop of the negative feedback structure, which can solve the technical problem of insufficient system stability and realize the construction of a stable and reliable automatic adjustment system. By performing direct and targeted frequency compensation on the loop, the system phase margin is improved, ensuring long-term stability of the output voltage. When the load current changes rapidly, the circuit can quickly adjust the conduction state of the N-channel MOSFET M1, thereby reducing the overshoot and undershoot of the output voltage and improving transient performance. The error amplifier compares the reference voltage with the feedback voltage obtained from the output voltage and outputs a control signal to adjust the conduction state of the N-channel MOSFET M1. This solves the problem of difficulty in efficiently, reliably, and accurately managing and converting higher input voltages due to insufficient stability and response speed. It provides a linear voltage regulation scheme with a better structure, easier compensation, high stability, and fast dynamic response, thereby efficiently and reliably providing accurate and stable low voltage for the internal circuitry of the chip.

[0013] Preferably, the voltage regulation circuit further includes a charge pump module. The input terminal of the charge pump module is connected to the input voltage VIN, and the output terminal is connected to the power supply terminal of the error amplifier. The charge pump module is used to provide the error amplifier with an operating voltage higher than the input voltage VIN, so as to ensure that the error amplifier outputs the control signal that fully drives the N-channel MOSFET M1.

[0014] In this embodiment, the input terminal of the charge pump module is connected to the input voltage VIN, and the output terminal is connected to the power supply terminal of the error amplifier. This provides the error amplifier with an operating voltage higher than the input voltage VIN, ensuring that the error amplifier outputs a control signal sufficient to drive the N-channel MOSFET M1, thus achieving sufficient driving capability across the entire input voltage range. Specifically, when the input voltage VIN is low (e.g., close to or lower than the required output voltage), the error amplifier in a conventional circuit structure will not be able to output a sufficiently high gate voltage to fully turn on the N-channel MOSFET M1, resulting in increased voltage drop, reduced efficiency, or even failure to regulate voltage properly. The charge pump in this embodiment provides an independent, higher power rail for the error amplifier by boosting the voltage, ensuring that it always outputs a gate control signal much higher than the source voltage (VOUT) of the N-channel MOSFET M1. This guarantees that the power transistor can be fully driven to a low-resistance state, significantly reducing the on-state voltage drop, improving circuit efficiency, and widening the circuit's minimum operating input voltage range.

[0015] Preferably, the voltage regulation circuit further includes a clamping module connected between the output of the error amplifier and the gate of the N-channel MOSFET M1. This clamping module limits the gate-source voltage of the N-channel MOSFET M1 within a preset safe range to prevent damage due to overvoltage. Further, the clamping module is a Zener diode or an active clamping circuit composed of transistors, and the clamping voltage of the clamping module is set according to the gate-source withstand voltage of the N-channel MOSFET M1.

[0016] In this embodiment, a clamping module is connected between the output of the error amplifier and the gate of the N-channel MOSFET M1. This module limits the gate-source voltage of the N-channel MOSFET M1 within a preset safe range, preventing damage due to overvoltage. This provides reliable overvoltage protection for the core power device, the N-channel MOSFET M1, enhancing circuit robustness. When using a charge pump, the gate drive voltage output by the error amplifier may exceed the gate-source (GS) withstand voltage of the N-channel MOSFET M1 (typically around 5V). Without protection, GS overvoltage will immediately cause permanent damage to the device. The clamping module added in this embodiment can monitor and limit the GS voltage in real time. Whether due to excessive charge pump voltage, loop oscillation, or other abnormal conditions, it clamps the GS voltage below a safe value, effectively preventing the power transistor from breaking down and significantly improving circuit reliability and lifespan.

[0017] Preferably, the voltage regulation circuit further includes a current limiting protection circuit. The current limiting protection circuit is electrically connected to the drain of the N-channel MOSFET M1 and the input voltage VIN, and is also electrically connected to the output terminal of the error amplifier and the gate of the N-channel MOSFET M1. It monitors the current flowing through the drain of the N-channel MOSFET M1 in real time, and directly limits the gate voltage of the N-channel MOSFET M1 when the current exceeds a preset threshold, so as to achieve overcurrent protection.

[0018] In this embodiment, the current-limiting protection circuit is electrically connected to the drain of the N-channel MOSFET M1 and the input voltage VIN, and also electrically connected to the output of the error amplifier and the gate of the N-channel MOSFET M1. It monitors the current flowing through the drain of the N-channel MOSFET M1 in real time, and directly limits the gate voltage of the N-channel MOSFET M1 when the current exceeds a preset threshold. This achieves fast and direct overcurrent protection, preventing circuit damage during output short circuits or overloads. This circuit directly monitors the power transistor current and, upon detecting an overcurrent, bypasses the conventional adjustment loop of the error amplifier, directly intervening and lowering the gate drive voltage, thereby forcibly limiting the output current. This direct limiting method in this embodiment has a fast response speed, acting before thermal or electrical stress damage to the power transistor and circuit, effectively limiting the current within a safe range, protecting the power transistor and the preceding power supply, and improving the safety and reliability of the circuit.

[0019] Furthermore, the current limiting protection circuit includes a metal resistor RCS and a current limiting module; one end of the metal resistor RCS is connected to the drain of the N-channel MOSFET M1 and the current limiting module, and the other end of the metal resistor RCS is connected to the input voltage VIN and the current limiting module; the current limiting module is electrically connected to the output terminal of the error amplifier and the gate of the N-channel MOSFET M1, and monitors the current flowing through the drain of the N-channel MOSFET M1 in real time through the metal resistor RCS, and directly limits the gate voltage of the N-channel MOSFET M1 when the current exceeds a preset threshold, so as to achieve overcurrent protection.

[0020] In this embodiment, a metal resistor RCS is connected in series in the main current path between the input voltage VIN and the drain of the N-channel MOSFET M1, enabling direct and lossless sampling of the power transistor current. The metal resistor has advantages such as a small temperature coefficient and high stability, ensuring the accuracy of the current detection value and preventing protection point misalignment due to temperature drift. The current limiting module accurately senses the current magnitude by monitoring the voltage drop across the metal resistor RCS in real time. Once an overcurrent is detected, the module does not adjust through a slow error amplifier loop, but directly intervenes in the gate voltage of the N-channel MOSFET M1, pulling the gate voltage down extremely quickly (response time in microseconds or even shorter), forcing the power transistor into the linear region or turning it off, thereby limiting the current within a preset safety threshold.

[0021] Preferably, the voltage setting feedback network includes a first resistor R1 and a second resistor R2 connected in series between the output voltage VOUT and ground, and a compensation capacitor C1 connected in parallel across the first resistor R1; the common connection point of the first resistor R1 and the second resistor R2 constitutes the signal feedback terminal, outputting the feedback voltage; the compensation capacitor C1 is used to perform frequency compensation on the feedback loop of the negative feedback structure. Furthermore, the compensation capacitor C1 introduces a zero in the loop frequency response to cancel an inherent pole in the loop, thereby increasing the loop's phase margin, simplifying the compensation design, and improving the load transient response.

[0022] In this embodiment, the voltage setting feedback network includes a first resistor R1 and a second resistor R2 connected in series between the output voltage VOUT and ground, and a compensation capacitor C1 connected in parallel across the first resistor R1. The common connection point of the first resistor R1 and the second resistor R2 constitutes the signal feedback terminal, outputting the feedback voltage. The compensation capacitor C1 is used to perform frequency compensation on the feedback loop of the negative feedback structure, enabling simultaneous setting of the output voltage and loop stability compensation. The voltage divider network formed by resistors R1 and R2 serves as a reference for setting a stable output voltage value, and its ratio directly determines the VOUT value when the feedback voltage equals the reference voltage. The capacitor C1 connected across R1 introduces a lead compensation network (i.e., a zero point) into the feedback path. This zero point can be used to cancel the low-frequency dominant poles introduced by other components in the feedback loop (such as error amplifiers and power transistors), which is a key means of performing frequency compensation and shaping the loop gain Bode plot, providing a specific circuit structure for fundamentally solving the system oscillation problem.

[0023] Preferably, the source of the N-channel MOSFET M1 is grounded through the voltage setting feedback network; the error amplifier controls the on-resistance of the N-channel MOSFET M1 by adjusting the gate voltage of the N-channel MOSFET M1, thereby achieving linear regulation and stabilization of the output voltage.

[0024] In this embodiment, the N-channel MOSFET M1 acts as a series regulator with source output. By changing its gate voltage, its on-resistance is continuously and linearly adjusted (rather than in a switching state), thereby creating a controllable voltage drop between the input voltage VIN and the output voltage VOUT. This linear adjustment method results in extremely low output voltage ripple and low noise, making it ideal for powering analog or RF circuits sensitive to power supply noise.

[0025] Preferably, all components of the voltage regulation circuit are integrated on a single chip, manufactured using BCD technology, forming a high-voltage power management chip, wherein the input voltage VIN ranges from 12V to 60V, and the output voltage is stabilized at 5V or 3.3V.

[0026] In this embodiment, all components of the voltage regulator circuit are integrated onto a single chip, manufactured using BCD technology, forming a high-voltage power management chip. The input voltage VIN ranges from 12V to 60V, and the output voltage is stabilized at 5V or 3.3V. This elevates the voltage regulator circuit to the chip-level product level, clearly defining its process applicability and specific performance indicators, resulting in core advantages such as small size, high reliability, good consistency, and ease of mass production. The BCD process can manufacture high-voltage power devices (such as high-voltage N-channel MOSFETs M1), precision analog circuits (such as error amplifiers), and digital control circuits on the same chip. The input voltage range (12V-60V) and typical output voltage (5V / 3.3V) provide application scenarios for the high-voltage power management chip of this embodiment, directly providing stable and clean power to low-voltage digital or analog loads from high-voltage buses in industries such as industry and automotive.

[0027] It should be noted that the above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention, and the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A voltage regulator circuit suitable for high-voltage power management chips, characterized in that, include: An error amplifier is provided, wherein the non-inverting input terminal of the error amplifier is electrically connected to the output terminal of a reference voltage source to receive a reference voltage. The error amplifier compares the reference voltage with a feedback voltage obtained from the output voltage and outputs a control signal for adjusting the conduction state of the N-channel MOSFET M1. The N-channel MOSFET M1 is electrically connected to the output terminal of the error amplifier and to the input voltage VIN, and is used to receive the control signal and drive the conduction state according to the received control signal. The error amplifier, the N-channel MOSFET M1, and the voltage setting feedback network constitute a negative feedback structure. The source of the N-channel MOSFET M1 is electrically connected to the voltage setting terminal of the voltage setting feedback network. The voltage setting feedback network generates the output voltage at the voltage setting terminal, acquires the output voltage to obtain the feedback voltage, and performs frequency compensation on the feedback loop of the negative feedback structure. The feedback voltage is connected to the inverting input terminal of the error amplifier through the signal feedback terminal of the voltage setting feedback network.

2. The voltage regulator circuit according to claim 1, characterized in that, It also includes a charge pump module, the input terminal of which is connected to the input voltage VIN, and the output terminal is connected to the power supply terminal of the error amplifier, for providing the error amplifier with an operating voltage higher than the input voltage VIN, so as to ensure that the error amplifier outputs the control signal that fully drives the N-channel MOSFET M1.

3. The voltage regulator circuit according to claim 2, characterized in that, It also includes a clamping module, which is connected between the output of the error amplifier and the gate of the N-channel MOS transistor M1, and is used to limit the gate-source voltage of the N-channel MOS transistor M1 within a preset safe range to prevent it from being damaged due to overvoltage.

4. The voltage regulator circuit according to claim 3, characterized in that, The clamping module is a Zener diode or an active clamping circuit composed of transistors, and the clamping voltage of the clamping module is set according to the gate-source withstand voltage of the N-channel MOS transistor M1.

5. The voltage regulator circuit according to claim 1, characterized in that, It also includes a current limiting protection circuit, which is electrically connected to the drain of the N-channel MOSFET M1 and the input voltage VIN, and electrically connected to the output of the error amplifier and the gate of the N-channel MOSFET M1. It monitors the current flowing through the drain of the N-channel MOSFET M1 in real time, and directly limits the gate voltage of the N-channel MOSFET M1 when the current exceeds a preset threshold, so as to achieve overcurrent protection.

6. The voltage regulator circuit according to claim 1, characterized in that, The voltage setting feedback network includes a first resistor R1 and a second resistor R2 connected in series between the output voltage VOUT and ground, and a compensation capacitor C1 connected in parallel across the first resistor R1; the common connection point of the first resistor R1 and the second resistor R2 constitutes the signal feedback terminal, which outputs the feedback voltage; the compensation capacitor C1 is used to perform frequency compensation on the feedback loop of the negative feedback structure.

7. The voltage regulator circuit according to claim 6, characterized in that, The compensation capacitor C1 introduces a zero in the loop frequency response to cancel out an inherent pole in the loop, thereby increasing the loop's phase margin, simplifying compensation design, and improving the load transient response.

8. The voltage regulator circuit according to claim 1, characterized in that, The source of the N-channel MOSFET M1 is grounded through the voltage setting feedback network; the error amplifier controls the on-resistance of the N-channel MOSFET M1 by adjusting the gate voltage of the N-channel MOSFET M1, thereby achieving linear regulation and stabilization of the output voltage.

9. The voltage regulator circuit according to claim 1, characterized in that, All components of the voltage regulation circuit are integrated on a single chip, manufactured using BCD technology, forming a high-voltage power management chip, wherein the input voltage VIN ranges from 12V to 60V, and the output voltage is stabilized at 5V or 3.3V.

10. A high-voltage power management chip, characterized in that, The high-voltage power management chip uses the voltage regulation circuit as described in any one of claims 1-9.

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