Control circuit and associated power converter circuit

Abstract

The utility model discloses a control circuit and related power converter circuit, control circuit is used for a power converter circuit, contains a feedback circuit, is used to produce a feedback signal according to an output voltage, an error amplifier circuit is used for comparing a reference voltage signal and the feedback signal to produce an error signal, a comparison circuit is used for comparing a compensation signal and a feedback adjustment signal, and according to it to control a power stage circuit, a ripple injection circuit is used to produce the compensation signal to the positive input of the comparison circuit according to the error signal and a signal of switch node, and a feedback adjustment circuit is used to produce the feedback adjustment signal to the negative input of the comparison circuit according to the feedback signal.

Description

Technical Field

[0001] This utility model relates to a control circuit and related power converter circuit, and more particularly to a control circuit and related power converter circuit that can improve stability and reliability. Background Technology

[0002] In existing technologies, the Constant On-Time (COT) control architecture is widely used in buck converters. The COT control architecture typically uses a comparator to compare a ramp signal and an error signal to control the on / off state of the power stage circuit, thereby regulating the output voltage. The ramp signal is generated by a ramp signal generator based on the voltage between the power stage circuit and the inductor, while the error signal is generated by an error amplifier comparing the output voltage with a reference voltage. However, due to the bandwidth limitations of the error amplifier, its output error signal often lags behind the ramp signal, potentially causing a control delay and failing to reflect changes in the output voltage in real time. Even worse, under certain operating conditions, the error signal and the ramp signal may change in the same direction, further reducing the accuracy of the comparison judgment.

[0003] Secondly, because the error signal lags behind the ramp signal and its trend may be in the same direction as the ramp signal, the comparator may generate two or more control pulses within a single pulse cycle, i.e., a double-pulse or multi-pulse phenomenon. This phenomenon will cause abnormal switching timing of the power stage circuit and result in abnormal disturbances or oscillations in the output voltage, leading to unexpected jitter. Furthermore, when the system is subjected to external interference, the lack of sufficient phase separation between the error signal and the ramp signal can easily cause false triggering of the comparator, further affecting the stability of the output voltage.

[0004] Therefore, overcoming the aforementioned control signal delay, insufficient noise immunity, and avoiding the generation of double or multiple pulses remain urgent issues to be addressed in this field. Utility Model Content

[0005] Therefore, the main objective of this invention is to provide a control circuit and related power converter circuit to improve the shortcomings of the prior art.

[0006] One embodiment of this utility model provides a control circuit for a power converter circuit, wherein the power converter circuit includes a power stage circuit and generates an output voltage via an inductor. The control circuit includes a feedback circuit for generating a feedback signal based on the output voltage; an error amplifier circuit for comparing a reference voltage signal and the feedback signal to generate an error signal; a comparator circuit including a positive input terminal for receiving a compensation signal and a negative input terminal for receiving a feedback adjustment signal, the comparator circuit comparing the compensation signal and the feedback adjustment signal to control the power stage circuit accordingly; a ripple injection circuit coupled to the error amplifier circuit, the positive input terminal of the comparator circuit, and a switching node between the power stage circuit and the inductor, for generating the compensation signal to the positive input terminal of the comparator circuit based on the error signal and a signal from the switching node; and a feedback adjustment circuit coupled to the feedback circuit and the negative input terminal of the comparator circuit, for generating the feedback adjustment signal to the negative input terminal of the comparator circuit based on the feedback signal.

[0007] The ripple injection circuit includes: a ripple generation circuit coupled to the switching node for generating a ripple signal based on the signal from the switching node; and a subtractor coupled to the error amplifier circuit, the positive input terminal of the comparator circuit, and the ripple generation circuit for reducing the error signal based on the ripple signal to generate the compensation signal.

[0008] The ripple generation circuit is a low-pass filter used to perform low-pass filtering on the signal of the switching node to generate the ripple signal.

[0009] Specifically, when the comparator circuit controls the power stage circuit to charge the inductor, the ripple signal rises to reduce the voltage of the compensation signal, thereby increasing the separation between the compensation signal and the feedback adjustment signal; and when the comparator circuit controls the power stage circuit not to charge the inductor, the ripple signal falls to increase the voltage of the compensation signal to cross the feedback adjustment signal.

[0010] The ripple injection circuit further includes a low-pass filter circuit for low-pass filtering the ripple signal to generate a low-pass filter result. The subtractor is further used to reduce the error signal based on the ripple signal and the low-pass filter result to generate the compensation signal.

[0011] The feedback adjustment circuit includes: an arithmetic circuit for generating an adjustment ripple signal based on the ripple signal or the ripple signal and the low-pass filtering result; and an adder circuit for increasing the feedback signal based on the adjustment ripple signal to generate the feedback adjustment signal.

[0012] The feedback adjustment circuit is used to directly output the feedback signal as the feedback adjustment signal.

[0013] It also includes a compensation circuit, one end of which is coupled between the error amplifier circuit and the ripple injection circuit, and the other end is coupled to a ground terminal.

[0014] Another embodiment of this utility model provides a power converter circuit for converting an input voltage into an output voltage, comprising: a switching node; an output terminal for outputting the output voltage; an inductor coupled between the switching node and the output terminal; a power stage circuit coupled to the input voltage and the switching node; a switching circuit coupled to the power stage circuit for controlling the power stage circuit to switch the input voltage according to a control signal; and a control circuit comprising: a feedback circuit for generating a feedback signal according to the output voltage; an error amplifier circuit for comparing a reference voltage signal and the feedback signal to generate an error signal; and a comparator circuit comprising a positive input terminal. A comparator circuit is used to receive a compensation signal, a negative input terminal for receiving a feedback adjustment signal, and a control terminal coupled to the switching circuit. The comparator circuit is used to compare the compensation signal with the feedback adjustment signal and output the control signal to the switching circuit through the control terminal. A ripple injection circuit is coupled to the error amplifier circuit, the positive input terminal of the comparator circuit, and the switching node, and is used to generate the compensation signal to the positive input terminal of the comparator circuit based on the error signal and a signal of the switching node. A feedback adjustment circuit is coupled to the feedback circuit and the negative input terminal of the comparator circuit, and is used to generate the feedback adjustment signal to the negative input terminal of the comparator circuit based on the feedback signal.

[0015] The ripple injection circuit includes: a ripple generation circuit coupled to the switching node for generating a ripple signal based on the signal from the switching node; and a subtractor coupled to the error amplifier circuit, the positive input terminal of the comparator circuit, and the ripple generation circuit for reducing the error signal based on the ripple signal to generate the compensation signal. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a power converter circuit according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of a ripple injection circuit according to an embodiment of the present invention.

[0018] Figure 3A This is a schematic diagram of a ripple injection circuit according to an embodiment of the present invention.

[0019] Figure 3B This is a schematic diagram of a ripple injection circuit according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of a ripple injection circuit according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of a feedback adjustment circuit according to an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the relevant signals of the power converter circuit in an embodiment of this utility model.

[0023] Figure 7 This is a schematic diagram of the relevant signals of the power converter circuit in an embodiment of this utility model.

[0024] Figure 8 This is a schematic diagram of a control flow according to an embodiment of the present utility model.

[0025] Figure labeling: 10 - Power converter circuit; VIN - Input voltage; VOUT - Output voltage; NP - Switching node; L - Inductor; 100 - Output terminal; COUT - Output capacitor; 12 - Power stage circuit; UG - Upper bridge switch; LG - Lower bridge switch; 14 - Switching circuit; 16 - Control circuit; CTRL - Control signal; IL - Inductor current; 140 - On-time controller; 144 - Switch driver; PWM - Pulse width modulation signal; 160 - Feedback circuit; 162 - Error amplifier circuit; 16 4 - Comparator circuit; + - Positive input terminal; -- - Negative input terminal; CT - Control terminal; 166 - Ripple injection circuit; 168 - Feedback adjustment circuit; 170 - Compensation circuit; NX - Node; VREF - Reference voltage signal; VFB - Feedback signal; ER - Error signal; COMPS - Compensation signal; VFB_S - Feedback adjustment signal; RC - Resistor; CC - Capacitor; GND - Ground terminal; S1 - Signal; RMP - Ripple signal; 20 - Ripple injection circuit; 200 - Ripple generation circuit; 202 - Subtractor; 30 - Ripple injection circuit; 302 - Ripple generation circuit; R1 - Resistor; R2 - Resistor; RF1 - Resistor; CF1 - Capacitor; VLP1 - Ripple signal; 304 - Subtractor; 3040 - Operational amplifier; 3042 - Operational amplifier; 3044 - Resistor; 3046 - Voltage-controlled current source; VR - Reference voltage; 32 - Ripple injection circuit; 322 - Ripple generation circuit; RF2 - Resistor; CF2 - Capacitor; VLP2 - Low-pass filter result; 324 - Subtractor; 3242 - Operational amplifier; 40 - Ripple signal Injection circuit; 400 - Ripple generation circuit; Irmp - Current; 402 - Subtractor; 4020 - Operational amplifier; 4022 - Resistor; 4024 - Switch; 50 - Feedback adjustment circuit; 500 - Operational circuit; 502 - Adder circuit; 5020 - Operational amplifier; 5022 - Resistor; 5024 - Voltage-controlled current source; 5026 - Switch; Vadj - Adjust ripple signal; Iadj - Current; 600~608, 700~704 - Curves; 80 - Control flow; 800~812 - Steps. Detailed Implementation

[0026] Please refer to Figure 1 , Figure 1This is a schematic diagram of a power converter circuit 10 according to an embodiment of the present invention. The power converter circuit 10 converts an input voltage VIN into an output voltage VOUT. It includes a switching node NP, an inductor L, an output terminal 100, a power stage circuit 12, a switching circuit 14, and a control circuit 16. The power stage circuit 12 includes an upper bridge switch UG and a lower bridge switch LG. The upper bridge switch UG is coupled between the input voltage VIN and the switching node NP, and the lower bridge switch LG is coupled between the switching node NP and a ground terminal GND. The inductor L is coupled between the switching node NP and the output terminal 100, and the output terminal 100 is coupled to an output capacitor COUT. The switching circuit 14 controls the on / off state of the upper bridge switch UG and the lower bridge switch LG according to a control signal CTRL generated by the control circuit 16, thereby switching the charging and discharging operation of the inductor L by the input voltage VIN. The input voltage VIN charges and discharges the inductor L, generating an inductor current IL, which in turn generates an output voltage VOUT of appropriate magnitude through the output capacitor COUT.

[0027] Specifically, the switching circuit 14 includes an on-time controller 140 and a switch driver 144. The on-time controller 140 receives the control signal CTRL, the input voltage VIN, and the output voltage VOUT, and generates a pulse-width modulation (PWM) signal (hereinafter referred to as the PWM signal) PWM to the switch driver 144. The switch driver 144 can then control the power stage circuit 12 according to the PWM signal PWM.

[0028] In the power converter circuit 10, the control circuit 16 includes a feedback circuit 160, an error amplifier circuit 162, a comparator circuit 164, a ripple injection circuit 166, a feedback adjustment circuit 168, and a compensation circuit 170. For ease of explanation, a node NX is formed between the error amplifier circuit 162, the ripple injection circuit 166, and the compensation circuit 170. The feedback circuit 160 is coupled to the output terminal 100 and is used to generate a feedback signal VFB to the error amplifier circuit 162 and the feedback adjustment circuit 168 based on the output voltage VOUT. The feedback circuit 160 can be a voltage divider circuit or a voltage follower, used to convert the output voltage VOUT into a feedback signal VFB suitable for comparison.

[0029] Error amplifier circuit 162 is coupled to feedback circuit 160 and node NX to compare a reference voltage signal VREF and feedback signal VFB to generate an error signal ER to node NX. That is, the error signal ER is related to the difference (VREF-VFB) between the reference voltage signal VREF and the feedback signal VFB. When power stage circuit 12 charges inductor L, the output voltage VOUT rises, and the feedback signal VFB also rises accordingly, causing the difference between the reference voltage signal VREF and the feedback signal VFB to decrease, thus the error signal ER shows a decreasing trend. When inductor L discharges (when inductor L is not charged), the output voltage VOUT decreases, and the feedback signal VFB also decreases accordingly, causing the difference between the reference voltage signal VREF and the feedback signal VFB to increase, thus the error signal ER shows an increasing trend.

[0030] Comparator circuit 164 is implemented via an operational amplifier, which includes a negative input terminal (in Figure 1 Marked as "-"), a positive input terminal (in) Figure 1 The circuit is labeled "+" and has a control terminal CT. The positive input terminal (+) receives a compensation signal COMPS generated by the ripple injection circuit 166, and the negative input terminal (-) receives a feedback adjustment signal VFB_S from the feedback adjustment circuit 168. The control terminal CT is coupled to the switching circuit 14. The comparator circuit 164 compares the compensation signal COMPS and the feedback adjustment signal VFB_S, and outputs a control signal CTRL to the on-time controller 140 of the switching circuit 14 based on the comparison result. Specifically, when the compensation signal COMPS continuously exceeds the feedback adjustment signal VFB_S (i.e., COMP ≥ VFB_S), the control signal CTRL output by the comparator circuit 164 can trigger the switching circuit 14 to control the power stage circuit 12 to operate according to a preset on-time, thereby increasing the inductor current IL and increasing the output voltage VOUT. Conversely, when the compensation signal COMPS is lower than the feedback adjustment signal VFB_S (i.e., COMP < VFB_S), the control signal CTRL output by the comparator circuit 164 controls the power stage circuit 12 to reduce the inductor current IL, thereby reducing the output voltage VOUT.

[0031] Ripple injection circuit 166 is coupled to node NX, the positive input (+) of comparator circuit 164, and switch node NP. It generates a compensation signal COMPS to the positive input (+) of comparator circuit 164 based on the error signal ER and a signal S1 from switch node NP. Ripple injection circuit 166 injects a ripple component into the error signal ER to generate the compensation signal COMPS. Feedback adjustment circuit 168 is coupled to feedback circuit 160 and the negative input (-) of comparator circuit 164. It generates a feedback adjustment signal VFB_S to the negative input (-) of comparator circuit 164 based on the feedback signal VFB. Compensation circuit 170 includes a resistor RC and a capacitor CC, connected in series between node NX and ground GND. It maintains the stability of the system's closed-loop bandwidth and controls the loop phase edge to prevent system instability caused by changes in input voltage VIN, output voltage VOUT, or load current.

[0032] As described above, the control circuit 16 generates the compensation signal COMPS and the feedback adjustment signal VFB_S to the positive input (+) and negative input (-) of the comparator circuit 164 respectively through the ripple injection circuit 166 and the feedback adjustment circuit 168. Under this architecture, the power converter circuit 10 of this invention can utilize the ripple injection circuit 166 and / or the feedback adjustment circuit 168 to make the compensation signal COMPS more easily crossover the feedback adjustment signal VFB_S when crossover is required, and to more clearly separate from the feedback adjustment signal VFB_S when separation is required, thereby effectively improving the noise tolerance of the comparator circuit 164. Specifically, when the power stage circuit 12 charges the inductor L (controlled by the switching circuit 14 according to the control signal CTRL), the error signal ER shows a decreasing trend, while the feedback signal VFB shows an increasing trend; when the inductor L discharges, the error signal ER shows an increasing trend, while the feedback signal VFB shows a decreasing trend. Therefore, by properly designing the ripple injection circuit 166 and / or the feedback adjustment circuit 168, the relationship between the compensation signal COMPS and the feedback adjustment signal VFB_S can be made to be more easily crossed or more clearly separated than the relationship between the error signal ER and the feedback signal VFB.

[0033] Therefore, the circuit architecture of the power converter circuit 10 provides design flexibility, allowing independent adjustment of the signals at the two input terminals of the comparator circuit 164 to optimize noise tolerance and transient response, and is suitable for power converter circuits under different operating conditions.

[0034] It should be noted that, Figure 1 The purpose is to explain the core architecture and operating principle of the power converter circuit 10. Those skilled in the art should design or adjust its circuit architecture appropriately according to system requirements, application areas, etc.

[0035] For example, please refer to Figure 2 , Figure 2 This is a schematic diagram of a ripple injection circuit 20 according to an embodiment of the present invention. The ripple injection circuit 20 is used to implement... Figure 1 The ripple injection circuit 166 includes a ripple generation circuit 200 and a subtractor 202. The ripple generation circuit 200 is coupled to the switching node NP and generates a ripple signal RMP based on the signal S1 from the switching node NP, providing the aforementioned ripple component. The ripple signal RMP generally exhibits a triangular waveform, with its rising phase corresponding to the charging of inductor L by the power stage circuit 12 (when the upper bridge switch UG is on), and its falling phase corresponding to the discharging phase of inductor L (when the lower bridge switch LG is on). The subtractor 202 is coupled to node NX, the ripple generation circuit 200, and the positive input (+) of the comparator circuit 164. It reduces the error signal ER based on the ripple signal RMP to generate a compensation signal COMPS, which is sent to the positive input (+) of the comparator circuit 164. For example, the subtractor 202 can subtract the ripple signal RMP from the error signal ER, i.e., COMPS = ER - RMP.

[0036] Therefore, the ripple injection circuit 20 can make the trend of the compensation signal COMPS opposite to that of the feedback adjustment signal VFB_S. That is, when the power stage circuit 12 charges the inductor L (charging stage), the feedback adjustment signal VFB_S shows an upward trend along with the feedback signal VFB, and the error signal ER decreases. The ripple component injected by the ripple injection circuit 20 (i.e., the ripple signal RMP) can strengthen the downward trend of the compensation signal COMPS, making the voltage of the compensation signal COMPS (compared to when the ripple component is not injected) even lower. When the inductor L discharges (discharging stage), the feedback adjustment signal VFB_S shows a downward trend along with the feedback signal VFB, and the error signal ER increases. The ripple component injected by the ripple injection circuit 20 can strengthen the upward trend of the compensation signal COMPS, making the voltage of the compensation signal COMPS (compared to when the ripple component is not injected) even higher. Therefore, the ripple injection circuit 20 can help the compensation signal COMPS to cross the feedback adjustment signal VFB_S more easily when crossover is required, and to separate more clearly from the feedback adjustment signal VFB_S when separation is required, thereby maintaining an appropriate degree of separation.

[0037] In addition, the ripple component injected by the ripple injection circuit 20 can effectively increase the noise margin between the compensation signal COMPS and the feedback adjustment signal VFB_S, and prevent the comparator circuit 164 from generating double pulses or multi pulses due to noise interference in a single pulse cycle. This prevents abnormal disturbances or oscillations in the output voltage VOUT, improves the overall stability and reliability of the system, and performs better in high-noise environments or under rapid load changes.

[0038] The ripple generation circuit 200 can be implemented in an appropriate manner to meet different requirements. For example, please refer to... Figure 3A , Figure 3A This is a schematic diagram of a ripple injection circuit 30 according to an embodiment of the present invention. The ripple injection circuit 30 is... Figure 2 A specific implementation circuit of the ripple injection circuit 20 includes a ripple generation circuit 302 and a subtractor 304. The ripple generation circuit 302 includes resistors R1, R2, RF1, and a capacitor CF1. Resistors R1 and R2 are connected in series between the switching node NP and ground GND, forming a voltage divider circuit. The common connection point between resistors R1 and R2 is then connected in series with resistor RF1 and capacitor CF1 to ground GND. Resistor RF1 and capacitor CF1 form a low-pass filter (or an integrator), and a ripple signal VLP1 is generated at its connection point (as...). Figure 2 The subtractor 304 includes operational amplifiers 3040 and 3042, a resistor 3044, and a voltage-controlled current source 3046. The positive input (+) of operational amplifier 3040 is coupled to node NX to receive the error signal ER, and its negative input (-) is connected to the output, forming a buffer. The positive input (+) of operational amplifier 3042 is coupled between resistor RF1 and capacitor CF1 to receive the ripple signal VLP1, and its negative input (-) is coupled to a reference voltage VR. The reference voltage VR can be a DC voltage or a 0-volt voltage. Operational amplifier 3042 controls the voltage-controlled current source 3046 to draw current from resistor 3044 based on the difference between the ripple signal VLP1 and the reference voltage VR, thereby generating a compensation signal COMPS. In other words, subtractor 304 reduces the error signal ER based on the ripple signal VLP1 to generate the compensation signal COMPS. In this way, the ripple injection circuit 30 can inject the ripple component (i.e., the ripple signal VLP1) into the error signal ER through subtraction, thereby strengthening the opposite trend between the compensation signal COMPS and the feedback adjustment signal VFB_S, so as to improve the noise tolerance and stability of the system.

[0039] Please refer to Figure 3B , Figure 3B This is a schematic diagram of a ripple injection circuit 32 according to an embodiment of the present invention. The ripple injection circuit 32 is... Figure 2 Another specific implementation of the ripple injection circuit 20, which is derived from the ripple injection circuit 30, is shown below; therefore, identical components are represented by the same symbols. The difference between the ripple injection circuit 32 and the ripple injection circuit 30 is that the ripple generation circuit 322 of the ripple injection circuit 32 adds a resistor RF2 and a capacitor CF2, which are connected in series between the ripple signal VLP1 and the ground terminal GND, compared to the ripple generation circuit 302 of the ripple injection circuit 30. See also... Figure 3BThe architecture of the ripple generation circuit 322, where resistors RF1 and RF2 and capacitors CF1 and CF2 can form a second-order low-pass filter (or a second-order integrator), can perform two low-pass filtering operations on the ripple signal VLP1 to produce a low-pass filtered result VLP2. Resistor RF1 and capacitor CF1 form the first-order low-pass filter circuit in the second-order low-pass filter, while resistor RF2 and capacitor CF2 form the second-order low-pass filter circuit. Furthermore, in the subtractor 324 of the ripple injection circuit 32, the negative input terminal (-) of an operational amplifier 3242 is compared to... Figure 3A Operational amplifier 3042 is modified to receive the low-pass filtered result VLP2. Operational amplifier 3242 controls voltage-controlled current source 3046 to draw current from resistor 3044 based on the difference between the ripple signal VLP1 and the low-pass filtered result VLP2, thereby generating the compensation signal COMPS. Furthermore, the operation of ripple injection circuit 32 is similar to that of ripple injection circuit 30; it can also inject ripple components into the error signal ER through subtraction, thereby strengthening the opposite trend between the compensation signal COMPS and the feedback adjustment signal VFB_S, thus improving the system's noise tolerance and stability.

[0040] It should be noted that, Figure 3B The second-order low-pass filter (second-order integrator) is only one embodiment; the order of the low-pass filter (integrator) can be determined according to system requirements, for example, it can be first-order, multi-order, or higher-order. The ripple signal VLP1 is the signal generated by the first-order low-pass filter circuit (integrator circuit) of a multi-order low-pass filter (multi-order integrator). Furthermore, in Figure 3A In the embodiments described, the ripple signal VLP1 can be considered as Figure 2 The ripple signal RMP (i.e., RMP = VLP1) is present in the signal; while... Figure 3B In this design, since subtractor 324 generates the ripple component based on the difference between the ripple signal VLP1 and the low-pass filter result VLP2, the ripple signal RMP can be considered as the result of VLP1 - VLP2. This integrated design can select an appropriate filter order and comparison benchmark according to the system noise characteristics and transient requirements to optimize the ripple injection effect of the compensation signal COMPS, thereby enhancing the crossover and separation between the compensation signal COMPS and the feedback adjustment signal VFB_S.

[0041] Please refer to Figure 4 , Figure 4 This is a schematic diagram of a ripple injection circuit 40 according to an embodiment of the present invention. The ripple injection circuit 40 is... Figure 2Another specific implementation of the ripple injection circuit 20 includes a ripple generation circuit 400 and a subtractor 402. The ripple generation circuit 400 is a voltage-controlled current source that generates a current Irmp as the ripple signal RMP based on the signal S1 from the switching node NP. The subtractor 402 includes an operational amplifier 4020, a resistor 4022, and a switch 4024. The operation of the operational amplifier 4020 and the resistor 4022 is similar to... Figure 3A , Figure 3B The operational amplifier 3040 and resistor 3044 in the circuit can be referred to the foregoing description. Switch 4024 can control the conduction relationship between ripple generation circuit 400 and resistor 4022 according to the PWM signal PWM generated by conduction time controller 140, thereby controlling the subtraction operation on the error signal ER. In other words, ripple injection circuit 40 can also inject ripple components (i.e., current Irmp) into the error signal ER through subtraction operation, thereby strengthening the opposite trend of compensation signal COMPS and feedback adjustment signal VFB_S, and improving the noise tolerance and stability of the system. It should be noted that, in addition to generating current Irmp according to signal S1 of switch node NP, in another embodiment, ripple generation circuit 400 can also generate current Irmp according to input voltage VIN, which is still within the scope of this utility model and is not limited thereto.

[0042] On the other hand, the feedback adjustment circuit 168 can also be implemented in an appropriate manner according to different requirements. In one embodiment, the feedback adjustment circuit 168 is a connecting line, in which case the feedback adjustment circuit 168 does not adjust the feedback signal VFB at all, but directly outputs the feedback signal VFB as the feedback adjustment signal VFB_S (VFB=VFB_S). In other embodiments, the feedback adjustment circuit 168 can increase the feedback signal VFB according to the way the ripple component injected into the error signal ER by the ripple injection circuit 166, so as to adjust the feedback signal VFB and generate the corresponding feedback adjustment signal VFB_S.

[0043] For example, please refer to Figure 5 , Figure 5 This is a schematic diagram of a feedback adjustment circuit 50 according to an embodiment of the present invention. The feedback adjustment circuit 50 is used to implement... Figure 1 The feedback adjustment circuit 168 includes an arithmetic circuit 500 and an adder circuit 502. The arithmetic circuit 500 can adjust according to... Figure 3A The ripple signal VLP1 or Figure 3BThe ripple signal VLP1 and the low-pass filter result VLP2 in the above circuit generate an adjustment ripple signal Vadj. The adder circuit 502 is coupled to the negative input (-) of the feedback circuit 160, the operational circuit 500, and the comparator circuit 160. It can amplify the feedback signal VFB according to the adjustment ripple signal Vadj, thereby generating a feedback adjustment signal VFB_S to the negative input (-) of the comparator circuit 160. Specifically, the adder circuit 502 includes an operational amplifier 5020, a resistor 5022, a voltage-controlled current source 5024, and a switch 5026. The voltage-controlled current source 5024 can generate a current Iadj to the switch 5026 according to the adjustment ripple signal Vadj. The operation of the operational amplifier 5020, resistor 5022, and switch 5026 is similar to... Figure 4 The combination of operational amplifier 4020, resistor 4022, and switch 4024 means that switch 5026 can control the conduction relationship between voltage control current source 5024 and resistor 5022 according to the PWM signal PWM generated by conduction time controller 140, thereby controlling the addition operation on the feedback signal VFB. Therefore, the feedback adjustment circuit 50 can inject the adjustment ripple signal Vadj into the feedback signal VFB through the adder circuit 502, thereby strengthening the changing trend of the feedback adjustment signal VFB_S, assisting in the crossing and separation of the compensation signal COMPS and the feedback adjustment signal VFB_S, and improving the system's noise immunity.

[0044] It should be noted that the adjustment ripple signal Vadj generated by the operational circuit 500 enhances the crossing and separation of the compensation signal COMPS and the feedback adjustment signal VFB_S. Therefore, the feedback adjustment signal VFB_S can be generated by using the reverse adjustment mode of the compensation signal COMPS. For example, if the feedback adjustment circuit 50 is paired with... Figure 3A If the ripple injection circuit 30 is used, the operational circuit 500 can generate an adjustment ripple signal Vadj based on the difference between the ripple signal VLP1 and the reference voltage VR (i.e., the output of the operational amplifier 3042). If the feedback adjustment circuit 50 is paired with... Figure 3B With the ripple injection circuit 32, the operational circuit 500 can generate an adjustment ripple signal Vadj based on the difference between the ripple signal VLP1 and the low-pass filter result VLP2 (i.e., the output of the operational amplifier 3242). Since the feedback adjustment circuit 50 performs addition on the feedback signal VFB, while the ripple injection circuit 30 or 32 performs subtraction on the error signal ER, when the same reference standard (i.e., the output of the operational amplifier 3042 or 3242) is adopted, the feedback adjustment circuit 50 and the ripple injection circuit 30 or 32 can produce an inverse adjustment effect. This can strengthen the crossing and separation of the compensation signal COMPS and the feedback adjustment signal VFB_S, further improving the system's noise immunity.

[0045] As can be seen from the above, the control circuit 16 has design flexibility, allowing independent adjustment of the signals at the two input terminals of the comparator circuit 164, which can achieve a simpler control method, a larger noise boundary and a faster transient response, thereby solving the problem of double pulse or multi-pulse phenomenon caused by the same direction change of the signal in the prior art, and improving the overall stability and reliability of the power converter circuit 10.

[0046] Please refer to Figure 6 and Figure 7 , Figure 6 and Figure 7 To adopt Figure 3A A schematic diagram of the relevant signals of the power converter circuit 10 when the ripple injection circuit 30 (reference voltage VR is a DC voltage or a 0-volt voltage) implements the ripple injection circuit 166. Figure 6 Curves 600 to 608 are displayed from top to bottom. Curve 600 represents the output voltage VOUT, curve 602 represents the inductor current IL, curve 604 represents the error signal ER, curve 606 represents the compensation signal COMPS, and curve 608 represents the ripple signal LP1.

[0047] Specifically, when the PWM signal PWM is, for example, at a high level, the upper bridge switch UG is turned on, the voltage of the switching node NP is at a high level, the inductor current IL (curve 602) increases, and the output voltage VOUT (curve 600) remains stable. At this time, the ripple generation circuit 302 generates a ripple signal VLP1 (curve 608) based on the signal S1 of the switching node NP, which shows an upward trend. The operational amplifier 3042 controls the voltage control current source 3046 to draw a current from the resistor 3044 based on the difference between the ripple signal VLP1 and the reference voltage VR, so as to inject the ripple component into the error signal ER (curve 604, downward trend), thereby generating a more decreasing compensation signal COMPS (curve 606). When the compensation signal COMPS crosses the feedback adjustment signal VFB_S, the comparator circuit 164 outputs the control signal CTRL, triggering the on-time controller 140 to reset the PWM signal PWM. When the PWM signal PWM turns to a low level, for example, the lower bridge switch LG is turned on, the inductor L discharges, and the inductor current IL (curve 602) decreases. At this time, the ripple signal VLP1 (curve 608) shows a downward trend. Operational amplifier 3042 controls voltage control current source 3046 to draw a current from resistor 3044 based on the difference between ripple signal VLP1 and reference voltage VR, so as to inject the ripple component into error signal ER (curve 604, upward trend), thereby generating rising compensation signal COMPS (curve 606). Crossover feedback adjustment signal VFB_S triggers the next charging cycle.

[0048] Figure 6The signal waveform diagram shows how ripple injection strengthens the opposite trend of the compensation signal COMPS and the feedback adjustment signal VFB_S, increases the separation, avoids multi-pulse phenomenon caused by noise interference, and thus ensures the stability and fast transient response of the output voltage VOUT.

[0049] also, Figure 7 Curves 700 to 704 are shown from top to bottom. Curve 700 represents the inductor current IL, curve 702 represents the feedback adjustment signal VFB_S, and curve 704 represents the compensation signal COMPS. Specifically, when the inductor current IL (curve 700) increases, the feedback adjustment signal VFB_S (curve 702) rises, and the compensation signal COMPS (curve 704) falls, increasing the separation between the two and avoiding noise interference. When the inductor current IL (curve 700) decreases, the feedback adjustment signal VFB_S (curve 702) falls, and the compensation signal COMPS (curve 704) rises, clearly triggering the control signal CTRL at the crossover point, maintaining system stability. Therefore, Figure 7 The signal waveform diagram shows a comparison between the feedback adjustment signal VFB_S and the compensation signal COMPS, highlighting the improved noise tolerance, preventing double pulse phenomenon, and ensuring the stability of the output voltage VOUT.

[0050] Depend on Figure 6 and Figure 7 As can be seen, this utility model, through the design of the ripple injection circuit 166 and the feedback adjustment circuit 168, effectively enhances the separation between the compensation signal COMPS and the feedback adjustment signal VFB_S, making the two more clearly separated in the non-crossover phase, thereby increasing noise tolerance and avoiding false triggering or multi-pulse phenomena caused by external interference; at the same time, in the crossover phase, the injection of ripple components makes the crossover more accurate and faster, ensuring the timely triggering of the control signal CTRL, improving transient response speed and overall system stability, and is particularly suitable for application environments with high noise or rapid load changes.

[0051] The operation of the power converter circuit 10 can be summarized as a control flow 80, such as... Figure 8 As shown, but not limited to, control flow 80 may include the following steps:

[0052] Step 800: Begin.

[0053] Step 802: Generate a feedback signal VFB based on the output voltage VOUT.

[0054] Step 804: Generate the error signal ER based on the reference voltage signal VREF and the feedback signal VFB.

[0055] Step 806: Generate the compensation signal COMPS based on the error signal ER and the signal S1 of the switching node NP.

[0056] Step 808: Generate feedback adjustment signal VFB_S based on feedback signal VFB.

[0057] Step 810: Compare the compensation signal COMPS with the feedback adjustment signal VFB_S, and control the power stage circuit 12 accordingly.

[0058] Step 812: End.

[0059] For a detailed description of control flow 80 and its derivative variations, please refer to the foregoing; they will not be repeated here.

[0060] In existing technologies, power converter circuits are prone to double-pulse or multi-pulse phenomena in high-noise environments due to insufficient noise tolerance of the comparator input signal, leading to unstable or oscillating output voltage. In contrast, this invention, through the ripple injection circuit 166 and the feedback adjustment circuit 168, enhances the separation between signals and ensures the accuracy of the crossover point, thereby significantly improving noise immunity and system stability. Furthermore, this invention allows for flexible selection of the implementation of the ripple injection circuit 166 and the feedback adjustment circuit 168, making it suitable for different application requirements and offering higher adaptability and reliability compared to existing technologies.

[0061] In summary, the embodiments of this utility model can effectively avoid the generation of double pulses or multiple pulses, and improve the stability and reliability of the system under high noise environment and rapid load change.

Claims

1. A control circuit for a power converter circuit, wherein the power converter circuit includes a power stage circuit and generates an output voltage via an inductor, characterized in that, The control circuit includes: A feedback circuit is used to generate a feedback signal based on the output voltage; An error amplifier circuit is used to compare a reference voltage signal and the feedback signal to generate an error signal; A comparator circuit includes a positive input terminal for receiving a compensation signal and a negative input terminal for receiving a feedback adjustment signal. The comparator circuit is used to compare the compensation signal and the feedback adjustment signal and control the power stage circuit accordingly. A ripple injection circuit is coupled to a switching node between the error amplifier circuit, the positive input terminal of the comparator circuit, and the power stage circuit and the inductor, and is used to generate a compensation signal to the positive input terminal of the comparator circuit based on the error signal and a signal of the switching node. as well as A feedback adjustment circuit is coupled to the negative input terminal of the feedback circuit and the comparator circuit, and is used to generate the feedback adjustment signal to the negative input terminal of the comparator circuit according to the feedback signal.

2. The control circuit as described in claim 1, characterized in that, The ripple injection circuit includes: A ripple generation circuit, coupled to the switching node, is used to generate a ripple signal based on the signal from the switching node; and A subtractor, coupled to the error amplifier circuit, the positive input terminal of the comparator circuit, and the ripple generation circuit, is used to reduce the error signal based on the ripple signal to generate the compensation signal.

3. The control circuit as described in claim 2, characterized in that, The ripple generation circuit is a low-pass filter used to low-pass filter the signal of the switching node in order to generate the ripple signal.

4. The control circuit as described in claim 2, characterized in that, When the comparator circuit controls the power stage circuit to charge the inductor, the ripple signal rises to reduce the voltage of the compensation signal, thereby increasing the separation between the compensation signal and the feedback adjustment signal; and when the comparator circuit controls the power stage circuit not to charge the inductor, the ripple signal falls to increase the voltage of the compensation signal to cross the feedback adjustment signal.

5. The control circuit as described in claim 2, characterized in that, The ripple injection circuit further includes a low-pass filter circuit for low-pass filtering the ripple signal to produce a low-pass filtered result. The subtractor is further used to reduce the error signal based on the ripple signal and the low-pass filtered result to produce the compensation signal.

6. The control circuit as described in claim 5, characterized in that, The feedback adjustment circuit includes: An operational circuit is used to generate an adjusted ripple signal based on the ripple signal or the ripple signal and the low-pass filter result; and An adder circuit is used to amplify the feedback signal based on the adjustment ripple signal to generate the feedback adjustment signal.

7. The control circuit as described in claim 1, characterized in that, The feedback adjustment circuit is used to directly output the feedback signal as the feedback adjustment signal.

8. The control circuit as described in claim 1, characterized in that, It also includes a compensation circuit, one end of which is coupled between the error amplifier circuit and the ripple injection circuit, and the other end is coupled to a ground terminal.

9. A power converter circuit for converting an input voltage into an output voltage, characterized in that, Include: One switch node; One output terminal is used to output the output voltage; An inductor is coupled between the switching node and the output terminal; A power stage circuit is coupled to the input voltage and the switching node; A switching circuit, coupled to the power stage circuit, is used to control the power stage circuit to switch the input voltage according to a control signal; and A control circuit, comprising: A feedback circuit is used to generate a feedback signal based on the output voltage; An error amplifier circuit is used to compare a reference voltage signal and the feedback signal to generate an error signal; A comparator circuit includes a positive input terminal for receiving a compensation signal, a negative input terminal for receiving a feedback adjustment signal, and a control terminal coupled to the switching circuit. The comparator circuit is used to compare the compensation signal with the feedback adjustment signal and output the control signal to the switching circuit through the control terminal accordingly. A ripple injection circuit is coupled to the error amplifier circuit, the positive input terminal of the comparator circuit, and the switching node, and is used to generate the compensation signal to the positive input terminal of the comparator circuit based on the error signal and a signal of the switching node. as well as A feedback adjustment circuit is coupled to the negative input terminal of the feedback circuit and the comparator circuit, and is used to generate the feedback adjustment signal to the negative input terminal of the comparator circuit according to the feedback signal.

10. The power converter circuit as described in claim 9, characterized in that, The ripple injection circuit includes: A ripple generation circuit, coupled to the switching node, is used to generate a ripple signal based on the signal from the switching node; and A subtractor, coupled to the error amplifier circuit, the positive input terminal of the comparator circuit, and the ripple generation circuit, is used to reduce the error signal based on the ripple signal to generate the compensation signal.

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