Switching Power Converter

Abstract

The present application provides a switching power converter, which includes a triangular wave generator, the input end of which is used to receive a clock signal; a load detection circuit, the input end of which is electrically connected to the output end of the switching power converter, and the first output end of which is electrically connected to the control end of the triangular wave generator, wherein the load detection circuit is used to control the amplitude of the triangular wave signal output by the triangular wave generator according to the output of the switching power converter. The switching power converter provided by the present application can improve the transient characteristics of the switching power converter when the output of the switching power converter changes.

Description

Technical Field

[0001] The present application relates to the field of circuits, and more particularly, to a switching power converter. Background Art

[0002] At present, in many circuits, switching power converters are used to improve the conversion efficiency of circuit power. However, in the switching power converter circuit, when the load of the switching power converter changes from a light load to a heavy load instantly, the output voltage of the switching power converter will drop rapidly, thereby reducing the performance of the electronic product system.

[0003] In conventional technology, the transient characteristics of a switching power converter are improved. For example, when the load of the switching power converter is light, the switching power converter is forced to operate in a pulse width modulation (PWM) mode and the number of output capacitors is increased to restore and maintain the output voltage stability of the switching power converter. Alternatively, the output voltage of the switching power converter is nonlinearly detected and controlled to restore and maintain the output voltage stability of the switching power converter. However, the above method is less effective in improving the transient characteristics of the switching power converter, resulting in a decrease in conversion efficiency or an increase in capacitor cost. Summary of the invention

[0004] The present application provides a switching power converter, which can improve the transient characteristics of the switching power converter when the output of the switching power converter changes.

[0005] In a first aspect, a switching power converter is provided, comprising: a triangular wave generator, an input end of the triangular wave generator being used to receive a clock signal; a load detection circuit, an input end of the load detection circuit being electrically connected to an output end of the switching power converter, a first output end of the load detection circuit being electrically connected to a control end of the triangular wave generator, wherein the load detection circuit is used to control the amplitude of a triangular wave signal output by the triangular wave generator according to the output of the switching power converter.

[0006] Compared with the fixed amplitude of the triangular wave signal used in the traditional switching power converter, in the embodiment of the present application, the amplitude of the triangular wave signal output by the triangular wave generator is controlled according to the output of the switching power converter. When the output voltage of the switching power converter drops, the switching power converter provided by the embodiment of the present application can restore the output voltage more quickly.

[0007] In combination with the first aspect, in certain implementations of the first aspect, the switching power converter also includes an error amplifier EA, wherein: the second output terminal of the load detection circuit is electrically connected to the control terminal of the EA, and the load detection circuit is also used to control the response speed of the signal output by the EA according to the output of the switching power converter.

[0008] Compared with the signal output by EA in a traditional switching power converter, in the embodiment of the present application, the signal output by the output control EA of the switching power converter has a higher response speed. When the output voltage of the switching power converter drops, the switching power converter provided by the embodiment of the present application can restore the output voltage more quickly.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the load detection circuit includes a first hysteresis comparator and a second hysteresis comparator, wherein: the first input end of the first hysteresis comparator is used to receive a first detection voltage, the second input end of the first hysteresis comparator is used to receive a first reference voltage, and the output end of the first hysteresis comparator is used to output a first signal, wherein the first detection voltage is a voltage obtained by the load detection circuit after conversion according to the received output current of the switching power converter; the first input end of the second hysteresis comparator is used to receive a second detection voltage, the second input end of the second hysteresis comparator is used to receive a second reference voltage, and the output end of the second hysteresis comparator is used to output a second signal, wherein the second detection voltage is a voltage after filtering the first detection voltage, the second reference voltage is less than or equal to the first reference voltage, and the first signal and the second signal are a signal for controlling the amplitude of the triangular wave output by the triangular wave generator and a signal for controlling the output of the EA.

[0010] In an embodiment of the present application, the value of the first reference voltage may be one or more; the value of the second reference voltage may be one or more. In combination with the first aspect, in certain implementations of the first aspect, the load detection circuit further includes a current detection circuit and a logic controller, wherein: the input end of the current detection circuit is electrically connected to the output end of the switching power converter, the output end of the current detection circuit is electrically connected to the first hysteresis comparator and the second hysteresis comparator, and the current detection circuit is used to convert the received output current of the switching power converter into the first detection voltage; the first input end of the logic controller is electrically connected to the output end of the first hysteresis comparator, and the second input end of the logic controller is electrically connected to the output end of the second hysteresis comparator; the logic controller is used to receive the first signal, and generates a fast load detection signal according to the first signal, the fast load detection signal is the signal output by the load detection circuit when the output current of the switching power converter increases rapidly; the logic controller is also used to receive the second signal, and generate a slow load detection signal according to the second signal, the slow load detection signal is the signal output by the load detection circuit when the output current of the switching power converter increases slowly; wherein, the fast load detection signal and the slow load detection signal are input signals of the control end of the triangular wave generator, and the fast load detection signal and the slow load detection signal are input signals of the control end of the EA.

[0011] In the embodiment of the present application, the introduction of a fast load detection signal and a slow load detection signal can improve the accuracy of the load detection circuit in identifying changes in the output of the switching power converter.

[0012] In a possible implementation, the switching power converter may include a plurality of first hysteresis comparators and a plurality of second hysteresis comparators, which respectively output a plurality of fast load detection signals and a plurality of slow load detection signals. The plurality of fast load detection signals and the plurality of slow load detection signals are used to adjust the magnitude of the triangular wave amplitude in the corresponding load interval when the switching power converter is in different load current intervals. For example, the process of the switching power converter from light load to heavy load can be divided into four load current intervals, and the four fast load detection signals and the four slow load detection signals output by the switching power converter can respectively adjust the magnitude of the triangular wave amplitude in the four load current intervals, thereby improving the accuracy of the control of the triangular wave amplitude.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the triangular wave generator includes a variable capacitor, a variable resistor and a triangular wave signal controller, wherein: the first end of the variable resistor is used to receive a clock signal, the second end of the variable resistor is electrically connected to the output end of the triangular wave generator, and the control end of the variable resistor is electrically connected to the output end of the triangular wave signal controller; the first end of the variable capacitor is electrically connected to the output end of the triangular wave generator, the second end of the variable capacitor is used to receive the output voltage of the switching power converter, and the control end of the variable capacitor is electrically connected to the output end of the triangular wave signal controller; the triangular wave signal controller is used to adjust the resistance value of the variable resistor and the capacitance value of the variable capacitor according to the fast load detection signal and the slow load detection signal received by the control end of the triangular wave generator.

[0014] In the embodiment of the present application, the triangle wave generator can adjust the amplitude of the triangle wave signal in segments, wherein the segmented adjustment of the amplitude of the triangle wave signal is completed within one clock cycle, or within multiple clock cycles.

[0015] In combination with the first aspect, in certain implementations of the first aspect, the triangle wave generator also includes an op amp, wherein: the first input terminal of the op amp is used to receive a reference voltage, the second input terminal of the op amp is electrically connected to the output terminal of the op amp, and the output terminal of the op amp is electrically connected to the first terminal of the variable capacitor.

[0016] In combination with the first aspect, in some implementations of the first aspect, the triangular wave generator includes an operational amplifier, a variable resistor, a variable current source, a variable current sink, a third switch, a fourth switch and a triangular wave signal controller, wherein: a first input terminal of the operational amplifier is used to receive a reference voltage, a second input terminal of the operational amplifier is electrically connected to an output terminal of the operational amplifier, and an output terminal of the operational amplifier is electrically connected to an output terminal of the triangular wave generator; a first terminal of the variable resistor is electrically connected between the third switch and the fourth switch, a second terminal of the variable resistor is electrically connected to the output terminal of the triangular wave generator, and a control terminal of the variable resistor is electrically connected to the output terminal of the triangular wave signal controller; the variable current source The first end of the variable current source receives a fixed voltage, the second end of the variable current source is electrically connected to the second end of the variable current sink, and the control end of the variable current source is electrically connected to the control end of the variable current sink and the output end of the triangular wave signal controller; the first end of the variable current sink is grounded; the third switch and the fourth switch are electrically connected between the second end of the variable current source and the second end of the variable current sink, and switch the third switch and the fourth switch according to the clock signal; the triangular wave signal controller is used to adjust the resistance value of the variable resistor, the current value of the variable current source, and the current value of the variable current sink according to the fast load detection signal and the slow load detection signal received by the control end of the triangular wave generator.

[0017] In combination with the first aspect, in certain implementations of the first aspect, the triangular wave generator also includes a first switch and a second switch, wherein: the first switch is electrically connected between the variable resistor and the fixed capacitor; the second switch is electrically connected between the DC voltage input terminal and the output terminal of the triangular wave generator; wherein the first switch and the second switch are alternately closed.

[0018] In combination with the first aspect, in certain implementations of the first aspect, the load detection circuit is further used to: increase the gain of the signal output by the EA; or increase the loop bandwidth of the signal output by the EA.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the EA includes an operational amplifier, a bias current source, a compensation network and an EA signal controller, wherein: the first input terminal of the operational amplifier is used to receive the output voltage of the switching power converter, the second input terminal of the operational amplifier is used to receive a reference voltage, and the output terminal of the operational amplifier is electrically connected to the output terminal of the EA; the first terminal of the compensation network is electrically connected to the output terminal of the operational amplifier, and the second terminal of the compensation network is grounded; the third input terminal of the operational amplifier is electrically connected to the bias current source; and the EA signal controller is used to adjust the bias current of the bias current source and adjust the parameters of the compensation network according to the fast load detection signal and the slow load detection signal received by the control terminal of the EA.

[0020] In combination with the first aspect, in certain implementations of the first aspect, the parameters of the compensation network include a variable resistor, a first variable capacitor, and a second variable capacitor, wherein: the first end of the variable resistor is electrically connected to the output end of the operational amplifier, and the second end of the variable resistor is electrically connected to the first end of the first variable capacitor; the second end of the first variable capacitor is grounded; the first end of the second variable capacitor is electrically connected to the output end of the operational amplifier, and the second end of the second variable capacitor is grounded; the control end of the variable resistor, the control end of the first variable capacitor, and the control end of the second variable capacitor are electrically connected to the output end of the EA signal controller; the resistance value of the variable resistor, the capacitance value of the first variable capacitor, and the capacitance value of the second variable capacitor are adjusted by the fast load detection signal and the slow load detection signal.

[0021] In a second aspect, a switching power converter is provided, comprising: a triangular wave generator, the input end of which is used to receive a clock signal; a load detection circuit, the load detection circuit comprising a first hysteresis comparator and a second hysteresis comparator, the input end of the first hysteresis comparator and the input end of the second hysteresis comparator are electrically connected to the input end of the load detection circuit, and the output end of the first hysteresis comparator and the output end of the second hysteresis comparator are electrically connected to the first output end of the load detection circuit, wherein: the first input end of the first hysteresis comparator is used to receive a first detection voltage, and the second input end of the first hysteresis comparator is used to receive a first detection voltage. The first input terminal of the load detection circuit is used to receive a first reference voltage, which is a voltage obtained by the load detection circuit after conversion according to the received output current of the switching power converter; the first input terminal of the second hysteresis comparator is used to receive a second detection voltage; the second input terminal of the second hysteresis comparator is used to receive a second reference voltage, which is a voltage after the first detection voltage is filtered, and the second reference voltage is less than or equal to the first reference voltage; wherein, the input terminal of the load detection circuit is electrically connected to the output terminal of the switching power converter, and the first output terminal of the load detection circuit is electrically connected to the triangle wave generator.

[0022] Compared with the traditional switching power converter, in the embodiment of the present application, a load detection circuit is introduced. According to the output of the first hysteresis comparator and the output of the second hysteresis comparator, the speed of the output change of the switching power converter can be known. It should be understood that according to the output of the first hysteresis comparator, the output of the switching power converter can be known to change rapidly, and according to the output of the second hysteresis comparator, the output of the switching power converter can be known to change slowly. In addition, according to the output of the first hysteresis comparator and the second hysteresis comparator of the load detection circuit, the response speed of the signal output by the EA can be controlled.

[0023] In combination with the second aspect, in certain implementations of the second aspect, the switching power converter further includes an error amplifier EA, wherein: the second output terminal of the load detection circuit is electrically connected to the control terminal of the EA.

[0024] Compared with the traditional switching power converter, in the embodiment of the present application, a load detection circuit is introduced. According to the output of the first hysteresis comparator and the output of the second hysteresis comparator, the speed of the output change of the switching power converter can be known. It should be understood that according to the output of the first hysteresis comparator, the output of the switching power converter can be known to change rapidly, and according to the output of the second hysteresis comparator, the output of the switching power converter can be known to change slowly. In addition, according to the output of the first hysteresis comparator and the second hysteresis comparator of the load detection circuit, the response speed of the signal output by the EA can be controlled.

[0025] In combination with the second aspect, in certain implementations of the second aspect, the load detection circuit also includes a current detection circuit and a logic controller, wherein: the input end of the current detection circuit is electrically connected to the output end of the switching power converter, and the output end of the current detection circuit is electrically connected to the first hysteresis comparator and the second hysteresis comparator; the first input end of the logic controller is electrically connected to the output end of the first hysteresis comparator, the second input end of the logic controller is electrically connected to the output end of the first hysteresis comparator, the first output end of the logic controller is electrically connected to the control end of the triangular wave generator, and the second output end of the logic controller is electrically connected to the control end of the EA.

[0026] In combination with the second aspect, in certain implementations of the second aspect, the triangular wave generator includes a variable capacitor, a variable resistor and a triangular wave signal controller, wherein: the first end of the variable resistor is used to receive a clock signal, the second end of the variable resistor is electrically connected to the first end of the variable capacitor and the output end of the triangular wave generator, and the control end of the variable resistor is electrically connected to the output end of the triangular wave signal controller; the second end of the variable capacitor is used to receive the output voltage of the switching power converter, and the control end of the variable capacitor is electrically connected to the output end of the triangular wave signal controller; the triangular wave signal controller is used to adjust the resistance value of the variable resistor and the capacitance value of the variable capacitor according to the fast load detection signal and the slow load detection signal received by the control end of the triangular wave generator.

[0027] In the embodiment of the present application, the triangle wave generator can adjust the amplitude of the triangle wave signal in segments, wherein the segmented adjustment of the amplitude of the triangle wave signal is completed within one clock cycle, or within multiple clock cycles.

[0028] In combination with the second aspect, in certain implementations of the second aspect, the triangle wave generator also includes an op amp, wherein: the first input terminal of the op amp is used to receive a reference voltage, the second input terminal of the op amp is electrically connected to the output terminal of the op amp, and the output terminal of the op amp is electrically connected to the first terminal of the variable capacitor.

[0029] In combination with the second aspect, in some implementations of the second aspect, the triangular wave generator includes an operational amplifier, a variable resistor, a variable current source, a variable current sink, a third switch, a fourth switch and a triangular wave signal controller, wherein: a first input terminal of the operational amplifier is used to receive a reference voltage, a second input terminal of the operational amplifier is electrically connected to an output terminal of the operational amplifier, and an output terminal of the operational amplifier is electrically connected to an output terminal of the triangular wave generator; a first terminal of the variable resistor is electrically connected between the third switch and the fourth switch, a second terminal of the variable resistor is electrically connected to the output terminal of the triangular wave generator, and a control terminal of the variable resistor is electrically connected to the output terminal of the triangular wave signal controller; the variable current source The first end of the variable current source is connected to a fixed voltage, the second end of the variable current source is electrically connected to the second end of the variable current sink, and the control end of the variable current source is electrically connected to the control end of the variable current sink and the output end of the triangular wave signal controller; the first end of the variable current sink is grounded; the third switch and the fourth switch are electrically connected between the second end of the variable current source and the second end of the variable current sink, and the third switch and the fourth switch are switched according to the clock signal; the triangular wave signal controller is used to adjust the resistance value of the variable resistor, the current value of the variable current source, and the current value of the variable current sink according to the fast load detection signal and the slow load detection signal received by the control end of the triangular wave generator.

[0030] In a possible implementation, the switching power converter may include a plurality of first hysteresis comparators and a plurality of second hysteresis comparators, which respectively output a plurality of fast load detection signals and a plurality of slow load detection signals. The plurality of fast load detection signals and the plurality of slow load detection signals are used to adjust the magnitude of the triangular wave amplitude in the corresponding load interval when the switching power converter is in different load current intervals. For example, the process of the switching power converter from light load to heavy load can be divided into four load current intervals, and the four fast load detection signals and the four slow load detection signals output by the switching power converter can respectively adjust the magnitude of the triangular wave amplitude in the four load current intervals, thereby improving the accuracy of the control of the triangular wave amplitude.

[0031] In combination with the second aspect, in certain implementations of the second aspect, the triangular wave generator also includes a first switch and a second switch, wherein: the first switch is electrically connected between the variable resistor and the fixed capacitor; the second switch is electrically connected between the DC voltage input terminal and the output terminal of the triangular wave generator; wherein the first switch and the second switch are alternately closed.

[0032] In combination with the second aspect, in certain implementations of the second aspect, the EA includes an operational amplifier, a bias current source, a compensation network and an EA signal controller, wherein: the first input terminal of the operational amplifier is used to receive the output voltage of the switching power converter, the second input terminal of the operational amplifier is used to receive a reference voltage, and the output terminal of the operational amplifier is electrically connected to the output terminal of the EA; the first terminal of the compensation network is electrically connected to the output terminal of the operational amplifier, and the second terminal of the compensation network is grounded; the third input terminal of the operational amplifier is electrically connected to the bias current source; and the EA signal controller is used to adjust the bias current of the bias current source and adjust the parameters of the compensation network according to the fast load detection signal and the slow load detection signal received by the control terminal of the EA.

[0033] In combination with the second aspect, in certain implementations of the second aspect, the parameters of the compensation network include a variable resistor, a first variable capacitor, and a second variable capacitor, wherein: the first end of the variable resistor is electrically connected to the output end of the operational amplifier, and the second end of the variable resistor is electrically connected to the first end of the first variable capacitor; the second end of the first variable capacitor is grounded; the first end of the second variable capacitor is electrically connected to the output end of the operational amplifier, and the second end of the second variable capacitor is grounded; the control end of the variable resistor, the control end of the first variable capacitor, and the control end of the second variable capacitor are electrically connected to the output end of the EA signal controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic circuit diagram of a switching power converter provided in an embodiment of the present application.

[0035] Figure 2 It is a schematic circuit diagram of a load detection circuit provided in an embodiment of the present application.

[0036] Figure 3 It is a schematic circuit diagram of a triangle wave generator provided in an embodiment of the present application.

[0037] Figure 4 It is a schematic circuit diagram of another triangle wave generator provided in an embodiment of the present application.

[0038] Figure 5 This is a schematic circuit diagram of another triangle wave generator provided in an embodiment of the present application.

[0039] Figure 6 is a schematic circuit diagram of an error amplifier circuit EA provided in an embodiment of the present application.

[0040] Figure 7 is a schematic circuit diagram of another error amplifier circuit EA provided in an embodiment of the present application.

[0041] Figure 8 It is a schematic diagram of the relationship between a load output voltage, an EA output signal, a triangular wave signal, and a load output current of a switching power converter provided in an embodiment of the present application.

[0042] Fig. 9 It is a schematic diagram of the relationship between a load output voltage, an EA output signal, a triangular wave signal, and a load output current of a switching power converter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0044] To facilitate understanding of the present application, before introducing the embodiments of the present application, a brief introduction is first given to concepts related to the switching power converter involved in the present application.

[0045] Switching mode power supply (SMPS): Switching power converters can be divided into two categories: AC-DC and DC-DC; switching power converters usually adopt buck step-down structure and boost step-up structure; the working modes of switching power converters can be divided into pulse frequency modulation (PFM) mode and PWM mode.

[0046] PFM mode: Usually implemented with a constant on-time or constant peak current in each switching cycle, the power supply operating frequency changes with the load or input and output conditions.

[0047] PWM mode: The usual implementation method is that the frequency of each switching cycle is fixed, and the switching duty cycle of each cycle changes with the load or input and output conditions.

[0048] Duty Ratio: refers to the percentage of the time a circuit is turned on to the entire circuit operating cycle.

[0049] For ease of understanding, the following describes the switching power converter in the embodiment of the present application by taking the switching power converter adopting the buck step-down structure as an example. Those skilled in the art can understand that the description in the following embodiment is only for example and not for limitation.

[0050] Figure 1 A schematic circuit diagram of a switching power converter provided in an embodiment of the present application is shown.

[0051] like Figure 1 As shown, the switching power converter includes a load detection circuit 310, a triangular wave generator 320, an error amplifier 330, a comparator 340, a logic control 350, a drive and power output stage 360, and a peripheral inductor and capacitor filter network 370. The load detection circuit 310 includes a current detection circuit 311, a first hysteresis comparator 312, a second hysteresis comparator 313, and a logic controller 314. The input end of the load detection circuit 310 is electrically connected to the output end of the switching power converter, the first output end of the load detection circuit is electrically connected to the control end of the triangular wave generator, and the second output end of the load detection circuit is electrically connected to the control end of the EA.

[0052] In an embodiment of the present application, the load detection circuit is used to control the amplitude of the triangular wave signal output by the triangular wave generator according to the output of the switching power converter, and the load detection circuit is also used to control the response speed of the signal output by the EA according to the output of the switching power converter.

[0053] Figure 2 A schematic circuit diagram of a load detection circuit provided in an embodiment of the present application is shown in FIG.

[0054] like Figure 2 As shown, the current detection circuit 311 includes adjustment tubes 101 and 102, current mirror tubes 103 and 104, error amplifiers 110 and 111, current sampling MOS tubes 120 and 121, power MOS field effect tubes 130 and 131, inductors 140 and capacitors 150. The input end of the current detection circuit is electrically connected to the output end of the switching power converter, the output end of the current detection circuit is electrically connected to the first hysteresis comparator and the second hysteresis comparator, and the current detection circuit is used to convert the received output current of the switching power converter into a voltage.

[0055] It should be understood that the function of the adjustment tubes 101 and 102 is that the adjustment tubes are controlled by the loop so that the voltage at each end of the sampling tube is equal to the voltage at each end of the power tube, thereby ensuring a high sampling accuracy. The function of the current mirror tubes 103 and 104 is to mirror the sampling current of the NMOS to the PMOS current output.

[0056] As an example, in the current detection circuit 311, the terminal voltages of the power MOS field effect transistors (110 and 111) and the current sampling MOS transistors (120 and 121) are clamped to the same voltage by error operational amplifiers (110 and 111), ensuring an accurate current sense ratio of the current sampling MOS transistors to the power transistors. The input of the current detection circuit is the output current of the switched-mode power supply converter. This output current is converted into the I_SENSE currents of the P and N transistors through the power MOS field effect transistors and the current sampling MOS transistors, and the I_SENSE currents of the P and N transistors are converted into the V_SENSE voltage through resistors.

[0057] The first hysteresis comparator 312, the first input terminal of the first hysteresis comparator is used to receive a first detection voltage, the second input terminal of the first hysteresis comparator is used to receive a first reference voltage, the output terminal of the first hysteresis comparator is used to output a first signal, and the output of the first hysteresis comparator is connected to the logic controller 314. Among them, the first detection voltage is a voltage obtained after the load detection circuit converts the received output current of the switched-mode power supply converter.

[0058] The second hysteresis comparator 313, the first input terminal of the second hysteresis comparator is used to receive a second detection voltage, the second input terminal of the second hysteresis comparator is used to receive a second reference voltage, the output terminal of the second hysteresis comparator is used to output a second signal, and the output of the second hysteresis comparator is connected to the logic controller 314. Among them, the second detection voltage is the voltage after the first detection voltage is filtered, and the second reference voltage is less than or equal to the first reference voltage.

[0059] In the embodiments of the present application, the value of the first reference voltage can be one or multiple; the value of the second reference voltage can be one or multiple.

[0060] The logic controller 314, the first input terminal of the logic controller is electrically connected to the output terminal of the first hysteresis comparator, and the second input terminal of the logic controller is electrically connected to the output terminal of the second hysteresis comparator; the logic controller is used to receive the first signal and generate a fast load detection signal according to the first signal. The fast load detection signal is a signal output by the load detection circuit when the output current of the switched-mode power supply converter rapidly increases; the logic controller is also used to receive the second signal and generate a slow load detection signal according to the second signal. The slow load detection signal is a signal output by the load detection circuit when the output current of the switched-mode power supply converter slowly increases; among them, the fast load detection signal and the slow load detection signal are input signals to the control terminal of the triangular wave generator, and the fast load detection signal and the slow load detection signal are input signals to the control terminal of the EA.

[0061] As an example, the working process of the load detection circuit in the embodiments of the present application is as follows:

[0062] The load detection circuit receives the output current from the switching power converter, and the output current is converted into a V_SENSE voltage through the current detection circuit 311;

[0063] The first end of the first hysteresis comparator 312 is used to receive the V_SENSE voltage, the second end of the first hysteresis comparator 312 is used to receive the fast load detection threshold Vth_fast, and output a first signal; the first end of the second hysteresis comparator 312 is used to receive the filtered V_SENSE voltage, the second end of the second hysteresis comparator 312 is used to receive the slow load detection threshold Vth_slow, and output a second signal;

[0064] It should be understood that the threshold value Vth_fast for fast load detection in the embodiment of the present application may be one value or multiple values; the threshold value Vth_slow for slow load detection may be one value or multiple values.

[0065] The logic controller is used to receive a first signal and a second signal, and output a fast load detection signal according to the first signal, and output a slow load detection signal according to the second signal.

[0066] For example, when the V_SENSE received at the first end of the first hysteresis comparator 312 is greater than the fast load detection threshold Vth_fast received at the second end of the first hysteresis comparator 312, the first hysteresis comparator outputs a first signal with a logic value of 1, and the logic controller outputs a fast load detection signal with a logic value of 1 according to the first logic signal; when the filtered V_SENSE voltage received at the first end of the second hysteresis comparator 312 is less than the slow load detection threshold Vth_slow received at the second end of the second hysteresis comparator 312, the second hysteresis comparator outputs a second signal with a logic value of 0, and the logic controller outputs a slow load detection signal with a logic value of 0 according to the second logic signal.

[0067] For example, when the V_SENSE received at the first end of the first hysteresis comparator 312 is greater than the fast load detection threshold Vth_fast received at the second end of the first hysteresis comparator 312, the first hysteresis comparator outputs a first signal with a logic value of 1, and the logic controller outputs a fast load detection signal with a logic value of 1 according to the first logic signal; when the filtered V_SENSE voltage received at the first end of the second hysteresis comparator 312 is greater than the slow load detection threshold Vth_slow received at the second end of the second hysteresis comparator 312, the second hysteresis comparator outputs a second signal with a logic value of 1, and the logic controller outputs a slow load detection signal with a logic value of 1 according to the second logic signal.

[0068] For example, when the V_SENSE received at the first end of the first hysteresis comparator 312 is less than the fast load detection threshold Vth_fast received at the second end of the first hysteresis comparator 312, the first hysteresis comparator outputs a first signal with a logic value of 0, and the logic controller outputs a fast load detection signal with a logic value of 0 according to the first logic signal; when the filtered V_SENSE voltage received at the first end of the second hysteresis comparator 312 is greater than the slow load detection threshold Vth_slow received at the second end of the second hysteresis comparator 312, the second hysteresis comparator outputs a second signal with a logic value of 1, and the logic controller outputs a slow load detection signal with a logic value of 1 according to the second logic signal.

[0069] When both the logic value of the fast load detection signal and the logic value of the slow load detection signal are not 0, the amplitude of the triangular wave signal output by the triangular wave generator can be controlled according to the fast load detection signal and the slow load detection signal, and the response speed of the signal output by the EA can also be controlled. For example, when the logic value of the fast load detection signal is 1 and the logic value of the slow load detection signal is 0, the triangular wave generator is triggered to increase the amplitude of the triangular wave signal, and the increased amplitude of the triangular wave signal corresponds to the amplitude of the triangular wave signal required for loop stability when the switching power converter adopts the pulse width modulation mode. Alternatively, when the logic value of the fast load detection signal is 1 and the logic value of the slow load detection signal is 0, the response speed of the signal output by the EA is accelerated.

[0070] It should be understood that in the embodiment of the present application, the triangular wave generator is triggered to adjust the amplitude of the triangular wave signal in segments, wherein the segmented adjustment of the amplitude of the triangular wave signal is completed within one clock cycle, or within multiple clock cycles.

[0071] It should be understood that the accelerated response speed of the signal that triggers the EA output in the embodiment of the present application includes, but is not limited to, increasing the gain of the EA output signal and increasing the loop bandwidth of the EA.

[0072] When the logic values ​​of the fast load detection signal and the slow load detection signal are both 0, the amplitude of the triangle wave signal is switched or maintained to a smaller triangle wave signal amplitude in the PFM mode, and the EA output signal is switched or maintained to a faster response speed state in the PFM mode.

[0073] It should be understood that Figure 2 The load detection circuit shown in FIG. 1 is only an example and is not limiting.

[0074] The triangular wave generator 320 has an input terminal for receiving a clock signal and controls the amplitude of the triangular wave signal generated by the triangular wave generator according to the output of the load detection circuit 310 .

[0075] As an example, the switching power converter operates in a pulse frequency modulation mode, and the triangular wave generator 320 outputs a first triangular wave signal. When the load detection circuit 310 detects that the output load current of the switching power converter undergoes a transient change and causes the output voltage to drop, the triangular wave generator 320 is controlled to output a second triangular wave signal, wherein the second triangular wave signal corresponds to a pulse width modulation mode, and the amplitude value of the second triangular wave signal is higher than the amplitude value of the first triangular wave signal.

[0076] Figure 3-Figure 5 Three types of triangle wave generators provided by embodiments of the present application are shown.

[0077] Figure 3 A schematic circuit diagram of a triangle wave generator provided in an embodiment of the present application is shown.

[0078] like Figure 3 As shown, the triangle wave generator mainly includes a triangle wave signal controller, a variable resistor R1, a variable capacitor C2, a first switch S1, and a second switch S0.

[0079] The triangle wave signal controller is used to adjust the resistance value of the variable resistor R1 and the capacitance value of the variable capacitor C2 according to the fast load detection signal and the slow load detection signal received by the control end of the triangle wave generator to adjust the amplitude of the triangle wave signal.

[0080] The first end of the variable resistor R1 is used to receive the clock signal, the second end of the variable resistor R1 is electrically connected to the output end of the triangle wave generator, and the control end of the variable resistor R1 is electrically connected to the output end of the triangle wave signal controller;

[0081] A first end of the variable capacitor C2 is electrically connected to the output end of the triangular wave generator, a second end of the variable capacitor C2 is used to receive the output voltage of the switching power converter, and a control end of the variable capacitor C2 is electrically connected to the output end of the triangular wave signal controller;

[0082] The first switch S1 is electrically connected between the variable resistor R1 and the fixed capacitor C1; the second switch S0 is electrically connected between the DC voltage V_LINE input terminal and the output terminal RAMP_OUT of the triangle wave generator; wherein, at the same time, only one of the first switch S1 and the second switch S0 can be in a closed state. For example, the output of the triangle wave signal controller controls the first switch S1 to be closed and the second switch S0 to be opened. Alternatively, the output of the triangle wave signal controller controls the second switch S0 to be closed and the first switch S1 to be opened.

[0083] It should be understood that when the first switch S1 is closed and the second switch S0 is opened, the amplitude value of the triangular wave signal output by the triangular wave generator is not zero. When the first switch S1 is opened and the second switch S0 is closed, the amplitude value of the triangular wave signal output by the triangular wave generator is zero; if the output voltage ripple is considered, the triangular wave amplitude at this time is the coupling value of the output ripple through the capacitor. When the load of the switching power converter is light, the first switch S1 can be opened and the second switch S0 can be closed.

[0084] As an example, the process of the triangular wave generator of the embodiment of the present application outputting a triangular wave signal is as follows:

[0085] When switch S1 is closed and S0 is open, the center value of the triangular wave signal output by the triangular wave generator is obtained by dividing the output voltage VO of the switching power converter, and the amplitude of the triangular wave signal is generated by the CLK clock through the RC network composed of R1, C1 and C2. The signal output by the load detection circuit controls the gear change of the resistor R1 or the capacitor C2, thereby changing the amplitude of the triangular wave signal.

[0086] As another example, when the load of the switching power converter is light, switch S0 is closed and switch S1 is opened, and a triangular wave signal is generated by the DC voltage V_LINE. At this time, the amplitude of the triangular wave signal is 0, that is, the triangular wave generator outputs a straight line; if the output voltage ripple is considered, the triangular wave amplitude at this time is the coupling value of the output ripple through the capacitor.

[0087] Figure 4 A schematic circuit diagram of another triangle wave generator provided in an embodiment of the present application is shown.

[0088] like Figure 4 As shown, the triangle wave generator mainly includes a BUF operational amplifier, a triangle wave signal controller, a variable resistor R1, a variable capacitor C2, a first switch S1, and a second switch S0.

[0089] A BUF op amp, wherein the first input terminal of the BUF op amp is used to receive a reference voltage VREF_CENTRE; the second input terminal of the BUF op amp is electrically connected to the output terminal of the BUF op amp; and the output terminal of the BUF op amp is electrically connected to the first terminal of the variable capacitor C2.

[0090] The triangle wave signal controller is used to adjust the resistance value of the variable resistor R1 and the capacitance value of the variable capacitor C2 according to the fast load detection signal and the slow load detection signal received by the control end of the triangle wave generator to adjust the amplitude of the triangle wave signal.

[0091] The first switch S1 is electrically connected between the variable resistor and the fixed capacitor; the second switch S0 is electrically connected between the DC voltage input terminal and the output terminal of the triangular wave generator; wherein, at the same time, only one of the first switch S1 and the second switch S0 can be in a closed state.

[0092] It should be understood that when the first switch S1 is closed and the second switch S0 is opened, the amplitude value of the triangular wave signal output by the triangular wave generator is not zero. When the first switch S1 is opened and the second switch S0 is closed, the amplitude value of the triangular wave signal output by the triangular wave generator is zero; if the output voltage ripple is considered, the triangular wave amplitude at this time is the coupling value of the output ripple through the capacitor. When the load of the switching power converter is light, the first switch S1 can be opened and the second switch S0 can be closed.

[0093] As an example, the process of the triangular wave generator of the embodiment of the present application outputting a triangular wave signal is as follows:

[0094] When switch S1 is closed and S0 is open, the center value of the triangular wave signal output by the triangular wave generator is obtained by dividing the input voltage VREF_CENTRE of the BUF op amp, and the amplitude of the triangular wave signal is generated by the CLK clock through the RC network composed of R1, C1 and C2. The gear change of the resistor R1 or the capacitor C2 is controlled by the fast load detection signal and the slow load detection signal, thereby changing the amplitude of the triangular wave signal.

[0095] As another example, when the load of the switching power converter is light, switch S0 is closed and switch S1 is opened, and a triangular wave signal is generated by the DC voltage V_LINE. At this time, the amplitude of the triangular wave signal is 0, that is, the triangular wave generator outputs a straight line; if the output voltage ripple is considered, the triangular wave amplitude at this time is the coupling value of the output ripple through the capacitor.

[0096] In one embodiment, the switching power converter may include a plurality of first hysteresis comparators and a plurality of second hysteresis comparators, which respectively output a plurality of fast load detection signals and a plurality of slow load detection signals. The plurality of fast load detection signals and the plurality of slow load detection signals are used to adjust the magnitude of the triangular wave amplitude of the corresponding load interval when the switching power converter is in different load current intervals. For example, the process of the switching power converter from light load to heavy load can be divided into four load current intervals, and the four fast load detection signals and the four slow load detection signals output by the switching power converter can respectively adjust the magnitude of the triangular wave amplitude in the four load current intervals, thereby improving the accuracy of the control of the triangular wave amplitude.

[0097] Figure 5 A schematic circuit diagram of yet another triangle wave generator provided in an embodiment of the present application is shown.

[0098] like Figure 5 As shown, the triangular wave generator mainly includes a BUF op amp, a current source, a current sink, a triangular wave signal controller, a variable resistor R1, a first switch S1, a second switch S0, and a third switch Fourth switch

[0099] The first input terminal of the operational amplifier is used to receive a reference voltage, the second input terminal of the operational amplifier is electrically connected to the output terminal of the operational amplifier, and the output terminal of the operational amplifier is electrically connected to the output terminal of the triangle wave generator.

[0100] The first end of the variable current source receives a fixed voltage VDD, the second end of the variable current source is electrically connected to the second end of the variable current sink, the control end of the variable current source is electrically connected to the control end of the variable current sink and the output end of the triangle wave signal controller; the first end of the variable current sink is grounded.

[0101] The triangle wave signal controller is used to adjust the resistance value of the variable resistor R1, the current value of the variable current source and the current value of the variable current sink according to the fast load detection signal and the slow load detection signal received by the control end of the triangle wave generator to adjust the amplitude of the triangle wave signal.

[0102] The first end of the variable resistor R1 is electrically connected to the third switch And the fourth switch The second end of the variable resistor R1 is electrically connected to the output end of the triangle wave generator, and the control end of the variable resistor R1 is electrically connected to the output end of the triangle wave signal controller.

[0103] The first switch S1 is electrically connected between the variable resistor and the fixed capacitor; the second switch S0 is electrically connected between the DC voltage input terminal and the output terminal of the triangle wave generator; wherein, at the same time, only one of the first switch S1 and the second switch S0 can be in a closed state.

[0104] Third switch And the fourth switch The third switch is electrically connected between the second end of the variable current source and the second end of the variable current sink, and switches the third switch according to the clock signal CLK. And the fourth switch For example, when the CLK clock signal is high and input to the triangle wave generator, the switch closure, Alternatively, when the CLK signal is high and input to the triangle wave generator, the switch disconnect, closure.

[0105] As an example, the process of the triangular wave generator of the embodiment of the present application outputting a triangular wave signal is as follows:

[0106] When switch S1 is closed and switch S0 is opened, the center value of the triangular wave signal is provided by a fixed reference voltage VREF_CENTRE, and the amplitude of the triangular wave signal is generated by the CLK clock controlling a current source and a current sink to charge and discharge the RC network composed of R1, C1 and C2. The current range of the current source and current sink or the range change of the variable resistor R1 can be controlled by the fast detection signal and the slow load detection signal, so as to change the amplitude of the triangular wave signal output by the triangular wave generator.

[0107] As another example, when switch S0 is closed and switch S1 is opened, a triangular wave signal is generated by the DC voltage V_LINE. At this time, the amplitude of the triangular wave signal is 0, that is, the triangular wave generator outputs a straight line; if the output voltage ripple is considered, the triangular wave amplitude at this time is the coupling value of the output ripple through the capacitor.

[0108] It should be understood that Figure 3-Figure 5 The triangle wave generator shown in FIG. 1 is only an example and is not limiting.

[0109] The error amplifier EA 330 has a first input terminal for receiving a reference voltage and a second input terminal for receiving an output voltage of the switching power converter, and controls the response speed of the signal output by the EA according to the output of the load detection circuit 310 .

[0110] Figure 6 and Figure 7 Two types of error amplifiers EA provided by embodiments of the present application are shown.

[0111] Figure 6 A schematic circuit diagram of an error amplifier EA provided in an embodiment of the present application is shown.

[0112] like Figure 6 As shown, the error amplifier EA includes an operational amplifier 321 and a compensation network 322 .

[0113] Operational amplifier 321, the first input terminal of the operational amplifier is used to receive the output voltage of the switching power converter, the second input terminal of the operational amplifier is used to receive the reference voltage, the third input terminal of the operational amplifier is electrically connected to the bias current source, and the output terminal of the operational amplifier is electrically connected to the output terminal of the EA.

[0114] The compensation network 322 includes a variable resistor R1, a variable capacitor C1 and a variable capacitor C2. A first terminal of the compensation network is electrically connected to the output terminal of the operational amplifier, and a second terminal of the compensation network is grounded.

[0115] It should be understood that the EA also includes an EA signal controller, which is used to adjust the bias current of the bias current source and the parameters of the compensation network according to the fast load detection signal and the slow load detection signal received by the control end of the EA.

[0116] It should be understood that Figure 6 The connection relationship between the operational amplifier 321 and the compensation network 322 is only schematically drawn, wherein the resistance value of the variable resistor R1, the resistance value of the variable capacitor C1 and the resistance value of the variable capacitor C2 in the compensation network 322 can be adjusted in whole or in part by the fast load detection signal and the slow load detection signal output by the load detection circuit. The bias current of the bias current source can also be adjusted by the signal output by the load detection circuit to maintain the normal operation of the operational amplifier 321. The bias current can flow from the bias current source into the EA, or flow out from the EA to the ground.

[0117] Figure 7 A schematic circuit diagram of another error amplifier EA provided in an embodiment of the present application is shown.

[0118] like Figure 7 As shown, the error amplifier EA includes an operational amplifier 321 and a compensation network 322 .

[0119] Operational amplifier 321, the first input terminal of the operational amplifier is used to receive the output voltage of the switching power converter, the second input terminal of the operational amplifier is used to receive the reference voltage, the third input terminal of the operational amplifier is electrically connected to the bias current source, and the output terminal of the operational amplifier is electrically connected to the second end of the compensation network.

[0120] The compensation network 322 includes a variable resistor R2, a variable resistor R3, a variable capacitor C1, a variable capacitor C2 and a variable capacitor C3. A first terminal of the compensation network is electrically connected to a first input terminal of the operational amplifier, and an output terminal of the compensation network is connected to an output terminal of the operational amplifier.

[0121] It should be understood that the EA also includes an EA signal controller, which is used to adjust the bias current of the bias current source and the parameters of the compensation network according to the fast load detection signal and the slow load detection signal received by the control end of the EA.

[0122] It should be understood that Figure 7The connection relationship between the operational amplifier 321 and the compensation network 322 is only schematically drawn. The resistance value of the variable resistors (R2 and R3) and the capacitance value of the variable capacitors (C1, C2 and C3) in the compensation network can be adjusted in whole or in part by the signal output by the load detection circuit. The bias current of the EA bias current source can be adjusted by the fast load detection signal and the slow load detection signal output by the load detection circuit to maintain the normal operation of the operational amplifier 321. The bias current can flow from the bias current source into the EA, or flow out from the EA to the ground.

[0123] It should be understood that Figure 6 and Figure 7 The error amplifier EA shown in FIG. 1 is only an example and is not limiting.

[0124] The comparator 340 is used to receive the signal output by the error amplifier EA 330 and the triangular wave signal output by the triangular wave generator 320. The comparator 340 compares the signal output by the EA with the triangular wave signal and converts them into a square wave signal with a specific duty cycle. That is, the output of the comparator 340 is a PWM control signal.

[0125] The logic control 350 inputs include the PWM control signal output by the comparator 340, and other logic signals required for loop control. Among them, other logic signals required for loop control include but are not limited to overcurrent protection control signals, inductor current zero-crossing detection control signals, and loop state control signals. The output of the logic controller 350 is a logic signal that controls each power tube respectively. The control logic 350 processes the PWM control signal output by the comparator 340. For example, the control logic 350 can expand the pulse width of the PWM control signal output by the comparator 340, or the control logic 350 can reduce the pulse width of the PWM control signal output by the comparator 340.

[0126] The drive and power output stage 360 ​​includes a drive circuit, a dead zone control circuit, a power tube circuit, and an overcurrent detection circuit or a zero-crossing detection circuit. The input signal of the drive and power output stage 360 ​​is a control signal output by the logic control 350 for controlling the switch state of the power tube. The output signal of the drive and power output stage 360 ​​is a switch signal for driving the peripheral inductor and capacitor filter network.

[0127] The drive and power output stage 360 ​​processes the control signals output by the logic control 350, converts them into power tube gate drive signals with dead time, and then converts them into switch signals with power driving capability through the power tube. At the same time, the internal protection circuit can provide control signals such as overcurrent detection and inductor current zero-crossing detection.

[0128] The peripheral inductor and capacitor filter network 370 has a switching signal with power driving capability output by the drive and power output stage 360 ​​as input, and a DC voltage signal with specific power output capability, specific frequency, and specific ripple as output. The peripheral inductor and capacitor filter network 370 filters the switching signal with power driving capability and converts it into a DC voltage signal.

[0129] In conjunction with specific embodiments, Figure 1-Figure 9 , the working principle of the switching power converter mentioned in the embodiment of the present application is introduced in detail.

[0130] In a possible implementation, when the switching power converter operates in a pulse frequency modulation mode, the load of the switching power converter is a light load, and the triangular wave generator outputs a first triangular wave signal, which is determined according to the load of the switching power converter in the pulse frequency modulation mode. When the load of the switching power converter changes from a light load to a heavy load, the switching power converter changes from a pulse frequency modulation mode to a pulse width modulation mode, and the triangular wave generator outputs a second triangular wave signal, which is determined according to the loop stability of the switching power converter in the pulse width modulation mode. The amplitude value of the first triangular wave signal is lower than the amplitude value of the second triangular wave signal.

[0131] When the switching power converter changes from a light load to a heavy load, the output voltage of the switching power converter will drop. The amplitude of the triangular wave signal used in the switching power converter changes with the load of the switching power converter, which can quickly cut out a larger duty cycle when the output voltage drops, thereby restoring the stability of the output voltage more quickly.

[0132] As an example, when the switching power converter operates in the pulse frequency modulation mode, the load detection circuit outputs a fast load detection signal of 0 according to the detected output current of the switching power converter, and the slow load detection signal is also 0. The resistance value of the variable resistor and the capacitance value of the variable capacitor in the triangular wave generator are switched or maintained to output a small triangular wave amplitude gear or state. At this time, the triangular wave signal output by the triangular wave generator is a first triangular wave signal, and the amplitude value of the first triangular wave signal is Vpp0, see Figure 8 It should be understood that the amplitude value of the first triangular wave signal corresponds to the triangular wave signal output by the triangular wave converter when the switching power converter is lightly loaded.

[0133] When the load of the switching power converter changes from a light load to a heavy load, that is, the output voltage of the switching power converter drops, when the load detection circuit detects that the output voltage of the switching power converter drops, the value of the output fast load detection signal is 1, and the value of the slow load detection signal is also 0, triggering the resistance value of the variable resistor and the capacitance value of the variable capacitor in the triangular wave generator to change. At this time, the triangular wave signal output by the triangular wave generator is a second triangular wave signal, and the amplitude value of the second triangular wave signal is Vpp1, see Figure 8 It should be understood that the second triangular wave signal corresponds to the triangular wave signal required when the switching power converter operates in the pulse width modulation mode and the loop is stable.

[0134] It should be understood that since the variable resistor, variable capacitor, current source and current sink in the triangular wave generator are adjusted according to the signal output by the load detection circuit, the triangular wave signal output by the triangular wave generator is switched from the first triangular wave signal to the second triangular wave signal.

[0135] It should be understood that in the embodiment of the present application, when the first triangular wave signal is switched to the second triangular wave signal, the amplitude of the triangular wave signal can be adjusted in sections according to the load current of the switching power converter. Among them, the switching of the triangular wave signal can be completed within one clock cycle or within multiple clock cycles. The advantage of the switching method of one clock cycle is that the circuit design is simpler but the output voltage jitter caused by switching is slightly larger. The advantage of slow switching in multiple clock cycles is that the circuit design is more complicated but the output jitter caused by switching is smaller.

[0136] Optionally, when the load detection circuit detects that the output load current of the switching power converter increases slowly, the value of the fast load detection signal output by the load detection circuit is 0, and the value of the slow load detection signal is also 1.

[0137] Optionally, when the load detection circuit detects that the output load current of the switching power converter increases slowly and then increases quickly, the value of the output fast load detection signal is 1, and the value of the slow load detection signal is also 1.

[0138] In the embodiment of the present application, the amplitude of the triangular wave signal used in the switching power converter changes with the load of the switching power converter, and a larger duty cycle can be quickly cut out when the output voltage drops, thereby restoring the stability of the output voltage more quickly, see Figure 8 .

[0139] Figure 8 A schematic diagram showing the relationship between a load output voltage, a signal output by EA, a triangular wave signal, and a load output current of a switching power converter provided in an embodiment of the present application is shown.

[0140] like Figure 8 As shown, when the output voltage of the switching power converter drops, under the condition that the response speed of the signal output by EA remains the same, since the amplitude of the triangular wave signal changes with the load of the switching power converter, that is, the amplitude of the triangular wave signal switches from Vpp0 to Vpp1, the switching power converter proposed in the implementation of the present application can obtain a larger duty cycle more quickly when the output voltage drops, thereby recovering the output voltage more quickly.

[0141] In a possible embodiment, when the load of the switching power converter in the embodiment of the present application changes from a light load to a heavy load, that is, when the output voltage of the switching power converter drops, the EA outputs a signal with a faster response speed, see Fig. 9 .

[0142] When the switching power converter changes from a light load to a heavy load, the output voltage of the switching power converter will drop. The response speed of the signal output by EA in the switching power converter is relatively high, and a larger duty cycle can be quickly cut out when the output voltage drops, thereby restoring the stability of the output voltage more quickly.

[0143] As an example, when the switching power converter operates in the pulse frequency modulation mode, the load detection circuit outputs a fast load detection signal with a value of 0 based on the detected output current of the switching power converter, and the value of the slow load detection signal is also 0. Then, the resistance value of the variable resistor and the capacitance value of the variable capacitor in the EA are switched or maintained to a gear or state with a faster EA response speed. At this time, the signal output by the EA is the first EA signal.

[0144] When the load of the switching power converter changes from a light load to a heavy load, that is, the output voltage of the switching power converter drops, when the load detection circuit detects that the output voltage of the switching power converter drops, the value of the output fast load detection signal is 1, and the value of the slow load detection signal is also 0, triggering the resistance value of the variable resistor and the capacitance value of the variable capacitor in the EA to change. At this time, the signal output by the EA is the second EA signal. The response speed of the first EA signal is greater than the response speed of the second EA signal.

[0145] Optionally, when the load detection circuit detects that the output load current of the switching power converter increases slowly, the value of the fast load detection signal output by the load detection circuit is 0, and the value of the slow load detection signal is also 1.

[0146] Optionally, when the load detection circuit detects that the output load current of the switching power converter increases slowly and then increases quickly, the value of the output fast load detection signal is 1, and the value of the slow load detection signal is also 1.

[0147] In the embodiment of the present application, the response speed of the signal output by EA in the switching power converter is relatively high, and a larger duty cycle can be quickly cut out when the output voltage drops, thereby restoring the stability of the output voltage more quickly, see Fig. 9 .

[0148] Fig. 9 A schematic diagram showing the relationship between a load output voltage, a signal output by EA, a triangular wave signal, and a load output current of a switching power converter provided in an embodiment of the present application is shown.

[0149] like Fig. 9 As shown, when the output voltage of the switching power converter drops, under the condition that the triangular wave signal remains unchanged, since the signal output by EA has a faster response speed, the switching power converter proposed in the implementation of the present application can obtain a larger duty cycle more quickly when the output voltage drops, thereby recovering the output voltage more quickly.

[0150] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can 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 this application.

[0151] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0152] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0153] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0154] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0155] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0156] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A switching power converter, It is characterized in that include: A triangular wave generator, wherein an input end of the triangular wave generator is used to receive a clock signal; A load detection circuit, wherein an input end of the load detection circuit is electrically connected to an output end of the switching power converter, and a first output end of the load detection circuit is electrically connected to a control end of the triangular wave generator, wherein the load detection circuit is used to control the amplitude of the triangular wave signal output by the triangular wave generator according to a change in an output current of the switching power converter; The switching power converter further comprises an error amplifier EA, wherein the second output terminal of the load detection circuit is electrically connected to the control terminal of the EA, and the load detection circuit is further used to control the response speed of the signal output by the EA according to the output of the switching power converter; The load detection circuit comprises a first hysteresis comparator and a second hysteresis comparator, wherein: The first input terminal of the first hysteresis comparator is used to receive an input first detection voltage, the second input terminal of the first hysteresis comparator is used to receive a first reference voltage, and the output terminal of the first hysteresis comparator is used to output a first signal, wherein the first detection voltage is a voltage obtained by the load detection circuit after conversion according to the received output current of the switching power converter; The first input terminal of the second hysteresis comparator is used to receive a second detection voltage, the second input terminal of the second hysteresis comparator is used to receive a second reference voltage, and the output terminal of the second hysteresis comparator is used to output a second signal, wherein the second detection voltage is a voltage after filtering the first detection voltage, the second reference voltage is less than or equal to the first reference voltage, and the first signal and the second signal are a signal for controlling the amplitude of the triangular wave output by the triangular wave generator and a signal for controlling the output of the EA; The load detection circuit also includes a current detection circuit and a logic controller, wherein: The input end of the current detection circuit is electrically connected to the output end of the switching power converter, the output end of the current detection circuit is electrically connected to the first hysteresis comparator and the second hysteresis comparator, and the current detection circuit is used to convert the received output current of the switching power converter into a voltage; A first input terminal of the logic controller is electrically connected to an output terminal of the first hysteresis comparator, and a second input terminal of the logic controller is electrically connected to an output terminal of the second hysteresis comparator; The logic controller is used to receive the first signal and generate a fast load detection signal according to the first signal, wherein the fast load detection signal is a signal output by the load detection circuit when the output current of the switching power converter increases rapidly; The logic controller is further used to receive the second signal and generate a slow load detection signal according to the second signal, wherein the slow load detection signal is a signal output by the load detection circuit when the output current of the switching power converter increases slowly; The fast load detection signal and the slow load detection signal are input signals of the control end of the triangle wave generator, and the fast load detection signal and the slow load detection signal are input signals of the control end of the EA.

2. The switching power converter according to claim 1, It is characterized in that The triangular wave generator comprises a variable capacitor, a variable resistor and a triangular wave signal controller, wherein: The first end of the variable resistor is used to receive a clock signal, the second end of the variable resistor is electrically connected to the output end of the triangular wave generator, and the control end of the variable resistor is electrically connected to the output end of the triangular wave signal controller; The first end of the variable capacitor is electrically connected to the output end of the triangular wave generator, the second end of the variable capacitor is used to receive the output voltage of the switching power converter, and the control end of the variable capacitor is electrically connected to the output end of the triangular wave signal controller; The triangle wave signal controller is used to adjust the resistance value of the variable resistor and the capacitance value of the variable capacitor according to the fast load detection signal and the slow load detection signal received by the control end of the triangle wave generator.

3. The switching power converter according to claim 2, It is characterized in that The triangular wave generator also includes an operational amplifier, wherein: The first input terminal of the operational amplifier is used to receive a reference voltage, the second input terminal of the operational amplifier is electrically connected to the output terminal of the operational amplifier, and the output terminal of the operational amplifier is electrically connected to the first terminal of the variable capacitor.

4. The switching power converter according to claim 1, It is characterized in that The triangular wave generator comprises an operational amplifier, a variable resistor, a variable current source, a variable current sink, a third switch, a fourth switch and a triangular wave signal controller, wherein: The first input terminal of the operational amplifier is used to receive a reference voltage, the second input terminal of the operational amplifier is electrically connected to the output terminal of the operational amplifier, and the output terminal of the operational amplifier is electrically connected to the output terminal of the triangular wave generator; The first end of the variable resistor is electrically connected between the third switch and the fourth switch, the second end of the variable resistor is electrically connected to the output end of the triangular wave generator, and the control end of the variable resistor is electrically connected to the output end of the triangular wave signal controller; The first end of the variable current source receives a fixed voltage, the second end of the variable current source is electrically connected to the second end of the variable current sink, and the control end of the variable current source is electrically connected to the control end of the variable current sink and the output end of the triangular wave signal controller; A first end of the variable current sink is grounded; The third switch and the fourth switch are electrically connected between the second end of the variable current source and the second end of the variable current sink, and the third switch and the fourth switch are switched according to a clock signal; The triangle wave signal controller is used to adjust the resistance value of the variable resistor, the current value of the variable current source, and the current value of the variable current sink according to the fast load detection signal and the slow load detection signal received by the control end of the triangle wave generator.

5. The switching power converter according to any one of claims 2 to 4, It is characterized in that The triangular wave generator further comprises a first switch and a second switch, wherein: The first switch is electrically connected between the variable resistor and the fixed capacitor; The second switch is electrically connected between the DC voltage input terminal and the output terminal of the triangle wave generator; The first switch and the second switch are closed alternately.

6. The switching power converter according to claim 1, It is characterized in that The load detection circuit is further used for: increasing the gain of the signal output by the EA; or Increase the loop bandwidth of the signal output by the EA.

7. The switching power converter according to claim 1, It is characterized in that The EA includes an operational amplifier, a bias current source, a compensation network and an EA signal controller, wherein: The first input terminal of the operational amplifier is used to receive the output voltage of the switching power converter, the second input terminal of the operational amplifier is used to receive the reference voltage, and the output terminal of the operational amplifier is electrically connected to the output terminal of the EA; A first end of the compensation network is electrically connected to the output end of the operational amplifier, and a second end of the compensation network is grounded; The third input terminal of the operational amplifier is electrically connected to the bias current source; The EA signal controller is used to adjust the bias current of the bias current source and the parameters of the compensation network according to the fast load detection signal and the slow load detection signal received by the control end of the EA.

8. The switching power converter according to claim 7, It is characterized in that The parameters of the compensation network include a variable resistor, a first variable capacitor, and a second variable capacitor, wherein: A first end of the variable resistor is electrically connected to an output end of the operational amplifier, and a second end of the variable resistor is electrically connected to a first end of the first variable capacitor; The second terminal of the first variable capacitor is grounded; A first terminal of the second variable capacitor is electrically connected to the output terminal of the operational amplifier, and a second terminal of the second variable capacitor is grounded; A control end of the variable resistor, a control end of the first variable capacitor, and a control end of the second variable capacitor are electrically connected to an output end of the EA signal controller.

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