A high power linear regulator

Abstract

The invention provides a high-power linear voltage stabilizer, wherein the first input end of the first-stage feedback amplifier circuit receives a voltage given value; the output end of the first-stage feedback amplifier circuit is connected to the first input end of the second-stage feedback buffer circuit; the output end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear voltage stabilizer through the amplifier circuit; the second input end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear voltage stabilizer through the first compensation circuit; the second input end of the first-stage feedback amplifier circuit is connected to the output end of the high-power linear voltage stabilizer; the second compensation circuit is connected to the output end of the high-power linear voltage stabilizer; thereby, in the high-power linear voltage stabilizer with two feedback loops, the second-stage voltage loop is compensated, and the poles generated by the compensation circuit are compensated to achieve the compensation of fast transient response performance; the transient response and robust performance are better, and the compensation method has a simple structure, a small circuit area, a stable circuit and a low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of voltage stabilizers, and more specifically, particularly relates to a high-power linear voltage stabilizer. Background Art

[0002] The integrated LDO (Low Dropout Regulator) chips on the market currently have certain limitations on power, input voltage and output current. In order to avoid interference, some circuits that are sensitive to power ripple generally do not use DC power supply, so engineers usually build high-power LDOs on circuit boards to power the circuits.

[0003] In the design of LDO, loop compensation is generally involved. There are generally four compensation methods: Miller compensation, feedforward compensation, ESR zero compensation and the combination of the above compensation methods. Engineers will perform compensation based on the characteristics of the circuit to make the feedback system more stable.

[0004] In some systems that drive high current loads, the output pole and power tube gain may change dramatically due to the large load variation range, which may cause system oscillation and lead to loop stability problems. Traditional compensation methods cannot effectively cope with such a large variation range. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a high-power linear regulator for compensating the fast transient response performance of the high-power linear regulator.

[0006] The present application provides a high-power linear regulator, comprising: a first-stage feedback amplifier circuit, a second-stage feedback buffer circuit, an amplifier circuit, a first compensation circuit, and a second compensation circuit;

[0007] The first input terminal of the first-stage feedback amplifier circuit receives a voltage given value;

[0008] The output end of the first-stage feedback amplifier circuit is connected to the first input end of the second-stage feedback buffer circuit;

[0009] The output end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the amplifier circuit;

[0010] The second input end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the first compensation circuit;

[0011] The second input end of the first-stage feedback amplifier circuit is connected to the output end of the high-power linear regulator;

[0012] The second compensation circuit is connected to the output end of the high-power linear regulator.

[0013] Optionally, in the above-mentioned high-power linear regulator, the first compensation circuit includes: a first compensation capacitor, a first compensation resistor and a second compensation resistor;

[0014] One end of the first compensation capacitor connected in parallel with the first compensation resistor is connected to the output end of the high-power linear regulator; the other end is connected to the second-stage feedback buffer circuit, and the connection point is grounded through the second compensation resistor.

[0015] Optionally, in the above-mentioned high-power linear regulator, the second compensation circuit includes: a second compensation capacitor and a third compensation resistor connected in series.

[0016] Optionally, in the above-mentioned high-power linear regulator, the first-stage feedback amplifier circuit includes an operational amplifier circuit.

[0017] Optionally, in the above-mentioned high-power linear regulator, in the operational amplifier circuit:

[0018] The positive input terminal of the operational amplifier receives the voltage given value through the first resistor;

[0019] The inverting input terminal of the operational amplifier is connected to the output terminal of the high-power linear regulator through an eighth resistor;

[0020] The inverting input terminal of the operational amplifier is also grounded through a seventh resistor;

[0021] The power supply terminal of the operational amplifier is connected to the first power supply, and the ground terminal is grounded;

[0022] The output terminal of the operational amplifier is connected to the second-stage feedback buffer circuit through a second resistor.

[0023] Optionally, in the above-mentioned high-power linear regulator, the second-stage feedback buffer circuit is an emitter follower circuit.

[0024] Optionally, in the above-mentioned high-power linear regulator, in the emitter follower circuit:

[0025] The control terminal of the emitter follower is connected to the output terminal of the first-stage feedback amplifier circuit;

[0026] The emitter end of the emitter follower is connected to the first compensation circuit;

[0027] The output end of the emitter follower is connected to the amplifier circuit through a fourth resistor;

[0028] The output end of the emitter follower is also connected to the second power supply through a third resistor.

[0029] Optionally, in the above-mentioned high-power linear regulator, the emitter follower is a transistor.

[0030] Optionally, in the above-mentioned high-power linear regulator, the amplifying circuit includes: a switching tube;

[0031] The input end of the switch tube is connected to a second power supply;

[0032] The control end of the switch tube is connected to the output end of the second-stage feedback buffer circuit;

[0033] The output end of the switch tube is connected to the output end of the high-power linear regulator.

[0034] Optionally, in the above-mentioned high-power linear regulator, the switching tube is a triode or a MOS tube.

[0035] It can be seen from the above technical scheme that the present invention provides a high-power linear regulator, wherein the first input end of the first-stage feedback amplifier circuit receives a voltage given value; the output end of the first-stage feedback amplifier circuit is connected to the first input end of the second-stage feedback buffer circuit; the output end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the amplifier circuit; the second input end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the first compensation circuit; the second input end of the first-stage feedback amplifier circuit is connected to the output end of the high-power linear regulator; the second compensation circuit is connected to the output end of the high-power linear regulator; thereby, in the high-power linear regulator with two feedback loops, the second-stage voltage loop is compensated, and the poles generated by the second-stage feedback buffer circuit and the amplifier circuit are compensated to achieve compensation of fast transient response performance; therefore, the high-power linear regulator has excellent transient response, better robust performance, and the compensation method has a simple structure, a small circuit area, a stable circuit, and a low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 is a schematic diagram of a high-power linear regulator provided by an embodiment of the present invention;

[0038] Figure 2 is a schematic diagram of another high-power linear regulator provided by an embodiment of the present invention;

[0039] Figure 3is a schematic diagram of another high-power linear regulator provided by an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of a high-power linear voltage regulator in the prior art;

[0041] Figure 5 is a schematic diagram of another high-power linear regulator provided by an embodiment of the present invention;

[0042] Figure 6 It is a schematic diagram of the prior art providing a steady-state response of an LDO without load;

[0043] Figure 7 is a schematic diagram of a high-power linear regulator without load in a steady-state response provided by an embodiment of the present invention;

[0044] Figure 8 It is a schematic diagram of the prior art providing a LDO steady-state response with a load;

[0045] Fig. 9 It is a schematic diagram of a high-power linear regulator with load under steady-state response provided by an embodiment of the present invention;

[0046] Fig.10 It is a schematic diagram of the prior art providing LDO transient response under load;

[0047] Fig.11 It is a schematic diagram of a high-power linear regulator provided by an embodiment of the present invention under transient response and load application;

[0048] Fig.12 It is a schematic diagram of the prior art providing LDO transient response to load;

[0049] Fig.13 The present invention is a schematic diagram of a high-power linear regulator providing a transient response to unloading a load. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0052] The embodiment of the present application provides a high-power linear regulator, which is used to solve the problem in the prior art that in some systems driving high-current loads, the output pole and the power tube gain change drastically due to the large load variation range, and system oscillation may occur, resulting in loop stability problems. Traditional compensation methods cannot effectively deal with such a large variation range.

[0053] See also Figure 1 The high-power linear regulator includes: a first-stage feedback amplifier circuit, a second-stage feedback buffer circuit, an amplifier circuit, a first compensation circuit and a second compensation circuit.

[0054] The first input terminal of the first-stage feedback amplifier circuit receives the voltage given value Vref; that is, the first-stage feedback amplifier circuit receives the voltage given value Vref.

[0055] The second input terminal of the first-stage feedback amplifier circuit is connected to the output terminal of the high-power linear regulator. In other words, the first-stage feedback amplifier circuit also receives the output voltage Vout of the high-power linear regulator.

[0056] The output end of the first-stage feedback amplifier circuit is connected to the first input end of the second-stage feedback buffer circuit. In other words, the output signal of the first-stage feedback amplifier circuit is used as the output signal of the second-stage feedback buffer circuit, that is, the output signal of the first-stage feedback amplifier circuit is transmitted to the first input end of the second-stage feedback buffer circuit.

[0057] The output end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the amplifier circuit. That is, the output signal of the second-stage feedback buffer circuit is used as the input signal of the amplifier circuit, that is, the output signal of the second-stage feedback buffer circuit is transmitted to the input end of the amplifier circuit.

[0058] The second input end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the first compensation circuit. That is, the output signal of the high-power linear regulator is used as a feedback signal and transmitted to the second input end of the second-stage feedback buffer circuit through the first compensation circuit.

[0059] The second compensation circuit is connected to the output end of the high-power linear regulator. That is, the second compensation circuit compensates the output signal of the high-power linear regulator to avoid sudden changes in the output signal.

[0060] In this embodiment, the first input end of the first-stage feedback amplifier circuit receives a voltage given value Vref; the output end of the first-stage feedback amplifier circuit is connected to the first input end of the second-stage feedback buffer circuit; the output end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the amplifier circuit; the second input end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the first compensation circuit; the second input end of the first-stage feedback amplifier circuit is connected to the output end of the high-power linear regulator; the second compensation circuit is connected to the output end of the high-power linear regulator; thereby, in the high-power linear regulator with two feedback loops, the second-stage voltage loop is compensated, and the poles generated by the second-stage feedback buffer circuit and the amplifier circuit are compensated to achieve compensation for fast transient response performance; therefore, the high-power linear regulator has excellent transient response, better robust performance, and the compensation method has a simple structure, a small circuit area, a stable circuit, and a low cost.

[0061] It should be noted that if Figure 4 As shown, it shows a way to Figure 1 The first compensation circuit in the circuit is set between the input and output of the first-stage feedback amplifier circuit; that is, phase compensation is performed at the first-stage amplifier feedback circuit position to compensate for the poles generated by the second-stage feedback buffer circuit and the amplifier circuit. ESR zero compensation is used at the output end to shift the low-frequency pole generated by the load resistance and output capacitor to a high-frequency pole, which is much higher than the bandwidth of the op amp and does not affect the loop stability. Figure 4 The compensation circuit shown makes the phase margin of the loop within the stable range and enables the circuit to work normally. Figure 4 The circuit shown has poor transient response and steady-state response. When the load and input voltage change, the circuit has the disadvantages of high output ripple and peak voltage, long response time for the output voltage to change, and long time for the output voltage to stabilize again after the change.

[0062] In this embodiment, the first compensation circuit is arranged at the second-stage feedback buffer circuit, so that each pole before the crossover frequency in the system will increase the phase shift by 90°, and the system phase will be unstable when it reaches 180°. At present, there are two poles before the crossover frequency in the loop, one is the main pole generated by the amplifier, and the other is the secondary main pole generated by the amplifier circuit. Therefore, a zero point is added to the compensation circuit to reduce the 90° phase shift and stabilize the loop; that is, by compensating the second-stage voltage loop, compensating the poles generated by the second-stage feedback buffer circuit and the amplifier circuit, the compensation method with fast transient response performance is used to make the loop stable and the output normal.

[0063] In practical applications, such as Figure 2 As shown, the first compensation circuit includes: a first compensation capacitor Cf, a first compensation resistor Rf and a second compensation resistor R5.

[0064] One end of the first compensation capacitor Cf and the first compensation resistor Rf connected in parallel is connected to the output end of the high-power linear regulator; the other end is connected to the second-stage feedback buffer circuit, and the connection point is grounded to GND through the second compensation resistor R5.

[0065] Specifically, one end of the first compensation capacitor Cf is connected to one end of the first compensation resistor Rf, and the connection point is connected to the output end of the high-power linear regulator to receive the output signal of the high-power linear regulator; the other end of the first compensation capacitor Cf is connected to the other end of the first compensation resistor Rf, and the connection points are respectively connected to the second input end of the second-stage feedback buffer circuit and one end of the second compensation resistor R5, and the other end of the second compensation resistor R5 is grounded GND.

[0066] It should be noted that, Vref is a given voltage value, Vout is an output voltage of a high-power linear regulator, VDD is a second power supply, Vfb1 is a feedback value received by a first-stage feedback amplifier circuit, and Vfb2 is a feedback value received by a second-stage feedback buffer circuit.

[0067] In practical applications, the second compensation circuit includes: a second compensation capacitor Co and a third compensation resistor ESR connected in series.

[0068] Specifically, one end of the second compensation capacitor Co is connected to the output end of the high-power linear regulator to receive the output signal of the high-power linear regulator; the other end of the second compensation capacitor Co is connected to one end of the third compensation resistor ESR; the other end of the third compensation resistor ESR is grounded GND.

[0069] Alternatively, one end of the third compensation resistor ESR is connected to the output end of the high-power linear regulator to receive the output signal of the high-power linear regulator, and the other end of the third compensation resistor ESR is connected to one end of the second compensation capacitor Co, and the other end of the second compensation capacitor Co is grounded GND.

[0070] In practical applications, the first-stage feedback amplifier circuit includes an operational amplifier circuit.

[0071] That is to say, the operational amplification function of the first-stage feedback amplifier circuit is realized by the operational amplifier circuit.

[0072] Specifically, Figure 3 As shown, the operational amplifier circuit includes an operational amplifier U1 and corresponding resistors; the specific connection structure of the operational amplifier circuit is:

[0073] The positive input terminal of the operational amplifier U1 receives the voltage setting value Vref through the first resistor R1. That is, the positive input terminal of the operational amplifier U1 is connected to one end of the first resistor R1, and the other end of the first resistor R1 receives the voltage setting value Vref.

[0074] The inverting input terminal of the operational amplifier U1 is connected to the output terminal of the high-power linear regulator through the eighth resistor R8. That is, the inverting input terminal of the operational amplifier U1 is connected to one end of the eighth resistor R8, and the other end of the eighth resistor R8 is connected to the output terminal of the high-power linear regulator to receive the output signal of the high-power linear regulator.

[0075] The inverting input terminal of the operational amplifier U1 is also connected to the ground GND through the seventh resistor R7. That is, the inverting input terminal of the operational amplifier U1 is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 is connected to the ground GND.

[0076] The power supply terminal V+ of the operational amplifier U1 is connected to the first power supply VCC, and the ground GND terminal is connected to the ground GND.

[0077] The output end of the operational amplifier U1 is connected to the second stage feedback buffer circuit through the second resistor R2. That is, the output end of the operational amplifier U1 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the first end of the second stage feedback buffer circuit.

[0078] In practical applications, the second-stage feedback buffer circuit may be an emitter follower circuit.

[0079] Specifically, Figure 3 As shown, the emitter follower circuit includes an emitter follower Q1; the specific structure of the emitter follower circuit can be:

[0080] The control end of the emitter follower Q1 is connected to the output end of the first-stage feedback amplifier circuit; that is, the output signal of the first-stage feedback amplifier circuit can control the emitter follower Q1; when the output signal of the first-stage feedback amplifier circuit is at a high level, the emitter follower Q1 starts to work; when the output signal of the first-stage feedback amplifier circuit is at a low level, the emitter follower Q1 stops working. Of course, it is not limited to this, and will not be repeated here one by one, all of which are within the protection scope of this application.

[0081] An emitter terminal of the emitter follower Q1 is connected to the first compensation circuit.

[0082] The output end of the emitter follower Q1 is connected to the amplifier circuit through the fourth resistor R4. That is, the output end of the emitter follower Q1 is connected to one end of the fourth resistor R4, and the other end of the fourth resistor R4 is connected to the input and output ends of the amplifier circuit.

[0083] The output end of the emitter follower Q1 is also connected to the second power supply Vpower through the third resistor R3. That is, the output end of the emitter follower Q1 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the second power supply Vpower.

[0084] In practical applications, the emitter follower Q1 is a transistor, such as an NPN transistor, that is, the emitter of the transistor serves as the emitter end of the emitter follower Q1; the collector of the transistor serves as the output end of the emitter follower Q1; and the base of the transistor serves as the control end of the emitter follower Q1.

[0085] The emitter follower Q1 and the fourth resistor R4 provide base current for the amplifier circuit; the feedback circuit of the emitter follower circuit, the second compensation resistor R5, the first compensation capacitor Cf and the first compensation resistor Cf form a compensation circuit; the seventh resistor R7 and the eighth resistor R8 are the feedback network of the operational amplifier.

[0086] In practical applications, the amplifier circuit includes: a switch tube Q2.

[0087] The input end of the switch tube Q2 is connected to the second power supply Vpower; the control end of the switch tube Q2 is connected to the output end of the second-stage feedback buffer circuit; and the output end of the switch tube Q2 is connected to the output end of the high-power linear regulator.

[0088] Specifically, the switch tube Q2 is a triode or a MOS tube.

[0089] When the switch tube Q2 is a triode such as a PNP triode, the emitter of the triode serves as the output end of the switch tube Q2; the collector of the triode serves as the input end of the switch tube Q2; and the base of the triode serves as the control end of the switch tube Q2.

[0090] When the switch tube Q2 is a MOS tube, the drain of the MOS tube serves as the output end of the switch tube Q2; the source of the MOS tube serves as the input end of the switch tube Q2; and the gate of the MOS tube serves as the control end of the switch tube Q2.

[0091] From the above description, it can be seen that the first-stage feedback amplifier circuit is an operational amplifier circuit, and the second-stage feedback buffer circuit is an emitter follower circuit, so there are two feedback loops in the circuit, the operational amplifier feedback voltage loop and the emitter follower feedback voltage loop.

[0092] It is not difficult to see from the circuit that the second-stage feedback has a smaller loop, in which the loop includes out→Rf, Cf composed of a compensation circuit→Vfb2→NPN transistor→PNP transistor→Vout; so we add a compensation circuit to the feedback end of the second-stage loop. This compensation method is equivalent to adding a feedforward capacitor Cf to the feedback end of the transistor amplifier circuit. The function of the feedforward capacitor Cf is to make the phase advance in the second-stage voltage loop. The specific process is that when the output voltage Vout of the high-power linear regulator changes, the zero point generated by the feedforward capacitor Cf can make the phase of Vfb2 advance the phase of Vout, so that the second-stage feedback loop can quickly respond to the changes at the output end, and then the first-stage loop stabilizes the output voltage to the target value. After this series of feedback and adjustment, the circuit has excellent transient response capabilities.

[0093] The compensation circuit generates a low-frequency zero and a high-frequency pole in the system at the same time. The zero can compensate for the low-frequency pole generated by the base of the NPN transistor in the system, and the high-frequency pole falls outside the cross-over frequency of the system loop gain, so that the phase of the system meets the stability requirements.

[0094] Among them, the zero point is when the system input amplitude is not zero and the input frequency makes the system output zero, and this input frequency value is the zero point. The pole is when the system input amplitude is not zero and the input frequency makes the system output infinite, and this frequency value is the pole.

[0095] The zero-pole frequency generated by the compensation capacitor Cf

[0096] (1) Zero point:

[0097] (2) Pole:

[0098] Among them, f z is the zero point, fp is the pole; Rf||R5 represents the resistance after the resistors Rf and R5 are connected in parallel, that is: Rf||R5=Rf*R5 / (Rf+R5).

[0099] It should be noted that, according to the simulation results, the phase margin of the circuit is 25°. In other words, the output of the high-power linear regulator is stable.

[0100] Below, an example is given to illustrate the high-power linear regulator:

[0101] The high-power linear voltage stabilizer is applied to the transmission system of a channel machine. The second-stage amplifying transmission circuit thereof is powered by the voltage stabilizing circuit compensation method of the invention, achieving good results and improving the transmission ACTP index by 2 to 3 DB.

[0102] like Figure 5 As shown, it shows the selection of each component of the high-power linear regulator; that is, the first resistor R1 is a 1KΩ resistor, the second resistor R2 is a 200Ω resistor, the third resistor R3 is a 680Ω resistor, the fourth resistor R4 is a 10Ω resistor, the seventh resistor R7 is a 2.7KΩ resistor, the eighth resistor R8 is a 2.2KΩ resistor, the second compensation resistor R5 is a 150Ω resistor, the first compensation resistor Cf is a 330Ω resistor, and the third compensation resistor is a 3Ω resistor.

[0103] The first compensation capacitor Cf is a 39nF capacitor, and the second compensation capacitor Co is a 6.8uF capacitor.

[0104] Among them, the resistance parameter kΩ is kilo-ohm; the capacitance parameter nF is nanofarad; and the capacitance parameter uF is microfarad.

[0105] The model of transistor Q1 is QMMBT222ALT1 / ON, which is NPN type; the model of switch tube Q2 is QMJD45H11 / ON, which is PNP type. The model of operational amplifier U1 is LM2904.

[0106] The high-power linear regulator of the present application is compared with the existing LDO in terms of steady-state response and dynamic response, and whether or not there is a load.

[0107] 1. Steady-state response

[0108] 1. No load.

[0109] (1) Figure 6 As shown, the existing LDO has an output peak-to-peak value of 13.6V and a stabilization time of about 720us.

[0110] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp; VM (the bottom curve) is the input of the op amp.

[0111] (2) Figure 7 As shown, the high-power linear regulator provided by the present application has an output peak-to-peak value of 11.0V and a stabilization time of approximately 80us.

[0112] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp; VM (the bottom curve) is the input of the op amp.

[0113] 2. There is a load with a current of 2A.

[0114] (1) Figure 8 As shown, the existing LDO has an output peak-to-peak value of 14.2V and a stabilization time of about 430us.

[0115] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp; VM (the bottom curve) is the input of the op amp.

[0116] (2) Fig. 9 As shown, the high-power linear regulator provided by the present application has an output peak-to-peak value of 11.2V and a stabilization time of approximately 80us.

[0117] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp; VM (the bottom curve) is the input of the op amp.

[0118] 2. Transient Response

[0119] 1. The current suddenly changes from 0A to 3A with load.

[0120] (1) Fig.10 As shown, the existing LDO has an output peak-to-peak value of 470mV.

[0121] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp.

[0122] (2) Fig.11 As shown, the high-power linear regulator provided by the present application has an output peak-to-peak value of 400mV.

[0123] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp.

[0124] 2. The current suddenly changes from 3A to 0A to remove the load.

[0125] (1) Fig.12 As shown, the existing LDO has an output peak-to-peak value of 800mV.

[0126] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp.

[0127] (2) Fig.13As shown, the high-power linear regulator provided by the present application has an output peak-to-peak value of 470mV.

[0128] Vout (the top curve) is the output of the LDO circuit; VOA (the middle curve) is the output of the op amp.

[0129] Through the above comparison, it can be seen that the high-power linear regulator provided by the present application can achieve a compensation method for fast transient response performance to make the loop stable and the output normal.

[0130] The features recorded in the various embodiments in this specification can be replaced or combined with each other, and the same and similar parts between the various embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0131] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0132] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-power linear regulator, characterized in that: include: A first-stage feedback amplifier circuit, a second-stage feedback buffer circuit, an amplifier circuit, a first compensation circuit, and a second compensation circuit; The first input terminal of the first-stage feedback amplifier circuit receives a voltage given value; The output end of the first-stage feedback amplifier circuit is connected to the first input end of the second-stage feedback buffer circuit; The output end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the amplifier circuit; The second input end of the second-stage feedback buffer circuit is connected to the output end of the high-power linear regulator through the first compensation circuit; The second input end of the first-stage feedback amplifier circuit is connected to the output end of the high-power linear regulator; The second compensation circuit is connected to the output end of the high-power linear regulator; The first compensation circuit includes: a first compensation capacitor, a first compensation resistor and a second compensation resistor; one end of the first compensation capacitor connected in parallel with the first compensation resistor is connected to the output end of the high-power linear regulator; the other end is connected to the second-stage feedback buffer circuit, and the connection point is grounded through the second compensation resistor; The second compensation circuit comprises: a second compensation capacitor and a third compensation resistor connected in series; The first-stage feedback amplifier circuit includes an operational amplifier circuit; in the operational amplifier circuit: the positive input terminal of the operational amplifier receives the voltage set value through a first resistor; the reverse input terminal of the operational amplifier is connected to the output terminal of the high-power linear regulator through an eighth resistor; the reverse input terminal of the operational amplifier is also grounded through a seventh resistor; the power supply terminal of the operational amplifier is connected to a first power supply, and the ground terminal is grounded; the output terminal of the operational amplifier is connected to the second-stage feedback buffer circuit through a second resistor.

2. The high-power linear regulator according to claim 1, characterized in that: The second-stage feedback buffer circuit is an emitter follower circuit.

3. The high-power linear regulator according to claim 2, characterized in that: In the emitter follower circuit: The control terminal of the emitter follower is connected to the output terminal of the first-stage feedback amplifier circuit; The emitter end of the emitter follower is connected to the first compensation circuit; The output end of the emitter follower is connected to the amplifier circuit through a fourth resistor; The output end of the emitter follower is also connected to the second power supply through a third resistor.

4. The high-power linear regulator according to claim 3, characterized in that: The emitter follower is a triode.

5. The high-power linear regulator according to any one of claims 1 to 4, characterized in that: The amplifying circuit comprises: a switch tube; The input end of the switch tube is connected to a second power supply; The control end of the switch tube is connected to the output end of the second-stage feedback buffer circuit; The output end of the switch tube is connected to the output end of the high-power linear regulator.

6. The high-power linear regulator according to claim 5, characterized in that: The switch tube is a triode or a MOS tube.

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