PWM (Pulse Width Modulation) control circuit in current mode, switching power supply and electronic equipment

Abstract

The utility model provides a PWM (Pulse Width Modulation) control circuit in a current mode, a switching power supply and electronic equipment. The circuit comprises a first MOS (Metal Oxide Semiconductor) tube, a second MOS tube, a mutual inductor, a transformer, a latch, a first comparator, an error amplifier module, a current detection comparator module and a voltage comparator module, the drain electrode of the first MOS tube is connected with a voltage input end; a source electrode of the first MOS tube is connected with a transformer winding; the transformer winding is connected with an in-phase input end of a first comparator through an error amplifier module; the mutual inductor winding is connected with the inverted input end of the first comparator through the current detection comparator module; the output end of the first comparator is connected with the grid electrode of the first MOS tube through the latch; the transformer winding is further connected with the grid electrode of the second MOS tube through the voltage comparator module, and the source electrode of the second MOS tube is connected with the mutual inductor winding. According to the invention, the detection precision and flexibility of the PWM control circuit in the current mode can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic power technology field especially, and it is a kind of PWM control circuit, switching power supply and electronic equipment under current mode. BACKGROUND

[0002] Current mode PWM (Pulse Width Modulation) control technology is a control method for switching power supply. Unlike traditional voltage mode PWM control, current mode PWM control directly uses output current detection signal at the input end of PWM comparator to compare with the output signal of error amplifier, thereby realizing control of output pulse duty cycle, so that output current follows error voltage change. Since output current is directly detected, current mode PWM control responds faster to load change, can quickly adjust output pulse duty cycle, and improves transient response of the whole system. Common current detection method in prior art is to detect output current through a series resistor. Voltage across the series resistor is proportional to output current, and voltage signal of the series resistor is sent into PWM comparator, and PWM signal is generated by PWM comparator comparison, thereby controlling turn-on and turn-off of switching tube.

[0003] However, in high-power applications, in order to improve detection accuracy, a resistor with large resistance value is usually used. However, the larger the resistance value, the greater the power loss on the resistor. This not only increases the power consumption of the system, but also causes the resistor to heat up seriously, affecting the accuracy of voltage acquisition. Moreover, there is an upper limit to the detection voltage on the resistor, which cannot be too large. If the detection voltage is too large, it may exceed the input range of PWM comparator, resulting in inaccurate control. Due to the above disadvantages, current mode PWM control technology is limited in practical application. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of PWM control circuit, switching power supply and electronic equipment under current mode to solve above-mentioned technical problem, improve the detection accuracy and flexibility of PWM control circuit under current mode.

[0005] To solve the above technical problems, the utility model provides a kind of PWM control circuit under current mode, comprising: first MOS tube, second MOS tube, mutual inductor, transformer, latch, first comparator, error amplifier module, current detection comparator module and voltage comparator module.

[0006] The drain of the first MOS tube is connected with voltage input end;

[0007] The source of the first MOS tube is connected with one end of the primary winding of the mutual inductor, and the other end of the primary winding is connected with one end of the primary winding of the transformer;

[0008] One end of the secondary winding of the transformer is connected to the non-inverting input terminal of the first comparator through the error amplifier module;

[0009] One end of the secondary winding of the transformer is connected to the non-inverting input terminal of the first comparator through the error amplifier module;

[0010] The output terminal of the first comparator is connected to the gate of the first MOS tube through the latch;

[0011] One end of the secondary winding of the transformer is also connected to the gate of the second MOS tube through the voltage comparator module, and the other end of the secondary winding of the transformer is connected to the source of the second MOS tube.

[0012] In the above scheme, the transformer converts the current change of the primary winding into a voltage signal of the secondary winding, and the current detection comparator module compares the voltage signal with a reference signal to generate an accurate current feedback signal. Through the transformer and the current detection comparator module, the circuit can accurately detect the change of the load current. And the use of the transformer and the current detection comparator module replaces the large resistance, avoiding the high power consumption and heating problem caused by the large resistance. The error amplifier module compares the actual output voltage with the expected value to generate an error signal, and the first comparator compares the error signal with the output signal of the current detection comparator module to generate an accurate control signal. Through the error amplifier module and the first comparator, the circuit can accurately control the output voltage. The latch latches the output signal of the first comparator to generate a stable control signal for controlling the conduction and turn-off of the first MOS tube, ensuring that the accuracy of current control remains at a high level under different load conditions. The transformer converts the voltage of the primary winding into a voltage signal of the secondary winding, and the voltage comparator module compares the voltage signal with a reference signal to generate an accurate control signal to control the conduction and turn-off of the second MOS tube. Through the transformer and the voltage comparator module, the circuit can efficiently transmit energy.

[0013] In one implementation, the error amplifier module includes a first resistor, a second resistor, and an error amplifier, specifically:

[0014] The first end of the first resistor is connected to one end of the secondary winding of the transformer;

[0015] The second end of the first resistor is connected to the first end of the second resistor and the non-inverting input terminal of the error amplifier;

[0016] The non-inverting input terminal of the error amplifier is connected to a first reference voltage;

[0017] The output terminal of the error amplifier is connected to the non-inverting input terminal of the first comparator;

[0018] The other end of the primary winding of the transformer, the other end of the secondary winding of the transformer and the second end of the second resistor are grounded.

[0019] In an implementation, the current detection comparator module comprises a third resistor, a fourth resistor and a current detection comparator, specifically:

[0020] The first end of the third resistor, the first end of the fourth resistor and the non-inverting input of the current detection comparator are connected to one end of the secondary winding of the mutual inductor;

[0021] The second end of the third resistor, the source of the second MOS tube and the inverting input of the current detection comparator are connected to the other end of the secondary winding of the mutual inductor;

[0022] The second end of the fourth resistor is connected to the drain of the second MOS tube;

[0023] The output of the current detection comparator is connected to the inverting input of the first comparator.

[0024] In an implementation, the voltage comparator module comprises a current sampling resistor, a second amplifier and a second comparator, specifically:

[0025] The first end of the current sampling resistor is connected to one end of the secondary winding of the transformer and the non-inverting input of the second amplifier;

[0026] The second end of the current sampling resistor is connected to the inverting input of the second amplifier;

[0027] The output of the second amplifier is connected to the inverting input of the second comparator;

[0028] The non-inverting input of the second comparator is connected to a second reference voltage;

[0029] The output of the second comparator is connected to the gate of the second MOS tube.

[0030] In an implementation, the output of the first comparator is connected to the gate of the first MOS tube through the latch, specifically comprising:

[0031] The output of the first comparator is connected to the reset end of the latch;

[0032] The output of the latch is connected to the gate of the first MOS tube.

[0033] In a second aspect, the application further provides a switching power supply comprising the PWM control circuit in current mode as described above.

[0034] In a third aspect, the present application provides an electronic device comprising the switching power supply as described above. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 A connection relationship schematic diagram of a PWM control circuit in a current mode provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are used to illustrate the present application, but not to limit the scope of the present application.

[0037] The terms "first" and "second" and the like in the specification and claims of the present application and drawings are used to distinguish different objects, and are not used to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0038] Reference to "embodiments" in this document means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0039] Embodiment 1

[0040] Reference Figure 1 , Figure 1 A connection relationship schematic diagram of a PWM control circuit in a current mode provided in an embodiment of the present application. The embodiment of the present application provides a PWM control circuit in a current mode, comprising: a first MOS tube V1, a second MOS tube V2, a mutual inductor T1, a transformer T2, a latch RS1, a first comparator N2, an error amplifier module, a current detection comparator module and a voltage comparator module.

[0041] The drain of the first MOS tube V1 is connected with a voltage input end Vin+;

[0042] The source of the first MOS tube V1 is connected with one end of a primary winding of the mutual inductor, and the other end of the primary winding is connected with one end of a primary winding of the transformer T2;

[0043] One end of the secondary winding of the transformer T2 is connected to the non-inverting input terminal of the first comparator N2 through the error amplifier module;

[0044] One end of the secondary winding of the transformer T1 is connected to the inverting input terminal of the first comparator N2 through the current detection comparator module;

[0045] The output terminal of the first comparator N2 is connected to the gate of the first MOS V1 through the latch RS1;

[0046] One end of the secondary winding of the transformer T2 is also connected to the gate of the second MOS V2 through the voltage comparator module, and the source of the second MOS V2 is connected to the other end of the secondary winding of the transformer.

[0047] In the embodiment of the utility model, the source of the first MOS V1 is connected to one end of the primary winding of the transformer T1, the other end of the primary winding is connected to one end of the primary winding of the transformer T2, one end of the secondary winding of the transformer T1 is connected to the current detection comparator module, and the detected current signal is converted into a voltage signal and sent to the inverting input terminal of the first comparator N2. One end of the secondary winding of the transformer T2 is connected to the error amplifier module, and the detected voltage signal is amplified and converted into an error signal and sent to the non-inverting input terminal of the first comparator N2. The first comparator N2 compares the voltage signal sent by the current detection comparator module and the error signal sent by the error amplifier module, feeds back the comparison result to the latch RS1, latches the comparison result by the latch RS1 and outputs to the first MOS V1 to control the opening and closing of the first MOS. One end of the secondary winding of the transformer T2 is also connected to the voltage comparator module, compares the detected voltage signal with the reference voltage, generates a control signal and sends it to the gate of the second MOS V2. The voltage comparator module controls the conduction and turn-off of the second MOS V2 according to the comparison result, and can further adjust the output voltage.

[0048] In one embodiment, the error amplifier module comprises a first resistor R3, a second resistor R4 and an error amplifier N1, specifically: the first end of the first resistor R3 is connected to one end of the secondary winding of the transformer T2; the second end of the first resistor R3 is connected to the first end of the second resistor R4 and the inverting input terminal of the error amplifier N1; the non-inverting input terminal of the error amplifier N1 is connected to a first reference voltage UREF1; the output terminal of the error amplifier N1 is connected to the non-inverting input terminal of the first comparator N2; the other end of the primary winding of the transformer T2, the other end of the secondary winding of the transformer T2 and the second end of the second resistor R4 are grounded.

[0049] The error amplifier module is a key part in the current mode PWM control circuit, responsible for comparing the detected actual output voltage with the expected reference voltage, generating an error signal for subsequent voltage control. In the embodiment of the utility model, the secondary winding of transformer T2 converts the actual output voltage signal into a voltage signal, which is transmitted to the inverting input terminal of error amplifier N1 through first resistor R3. The non-inverting input terminal of the error amplifier is also connected to the expected output voltage value, i.e. the first reference voltage UREF1. The error amplifier compares the actual output voltage at the inverting input terminal with the reference voltage at the non-inverting input terminal, generates an error signal and outputs it to the non-inverting input terminal of first comparator N2.

[0050] In an embodiment, the current detection comparator module includes third resistor R1, fourth resistor R2 and current detection comparator N3, specifically: the first end of the third resistor R1, the first end of the fourth resistor R2 and the non-inverting input terminal of the current detection comparator N3 are connected to one end of the secondary winding of the mutual inductor T1; the second end of the third resistor R1, the source of the second MOS tube V2 and the inverting input terminal of the current detection comparator N3 are connected to the other end of the secondary winding of the mutual inductor T1; the second end of the fourth resistor R2 is connected to the drain of the second MOS tube; the output terminal of the current detection comparator N3 is connected to the inverting input terminal of the first comparator N2.

[0051] The current detection comparator module is another key part in the current mode PWM control circuit, responsible for converting the detected actual output current into a voltage signal and comparing it with the error signal to generate a control signal for subsequent current control. In the embodiment of the utility model, the secondary winding of the mutual inductor T1 converts the actual output current signal into a voltage signal, which is input to the non-inverting input terminal of the current detection comparator N3 after being divided by the third resistor R1 and the fourth resistor R2. The inverting input terminal of the current detection comparator N3 receives the voltage signal from the other end of the secondary winding of the mutual inductor, and the current detection comparator N3 compares the voltage signal at the non-inverting input terminal with the voltage signal at the inverting input terminal, generates a control signal and transmits it to the inverting input terminal of the first comparator N2 for subsequent current control.

[0052] In an embodiment, the voltage comparator module comprises a current sampling resistor R5, a second amplifier N4 and a second comparator N5, specifically: a first end of the current sampling resistor R5 is connected with one end of the secondary winding of the transformer T2 and a non-inverting input end of the second amplifier N4; a second end of the current sampling resistor R5 is connected with an inverting input end of the second amplifier N4; an output end of the second amplifier N4 is connected with an inverting input end of the second comparator N5; a non-inverting input end of the second comparator N5 is connected with a second reference voltage UREF2; and an output end of the second comparator N5 is connected with a gate of the second MOS tube V2.

[0053] The voltage comparator module is a key part in the current mode PWM control circuit, responsible for converting the detected actual output current into a voltage signal, comparing the voltage signal with a reference voltage, and generating a control signal for the on-off control of the second MOS tube V2. In the embodiment of the utility model, the secondary winding of the transformer T2 converts the actual output voltage signal into a voltage signal, which is converted into a current signal by the current sampling resistor R5. At the same time, the current sampling resistor R5 also converts the current signal into a voltage signal and inputs it into the non-inverting input end of the second amplifier N4. The inverting input end of the second amplifier N4 also receives the voltage signal from the current sampling resistor R5. The second amplifier N4 compares the voltage signal at the non-inverting input end with the voltage signal at the inverting input end, generates an amplified error signal, and then inputs the amplified error signal into the inverting input end of the second comparator N5. The non-inverting input end of the second comparator N5 is connected with the reference voltage corresponding to the expected output current, i.e. the second reference voltage UREF2. The second comparator N5 compares the error signal at the inverting input end with the second reference voltage UREF2 at the non-inverting input end, generates a control signal and outputs the control signal to the gate of the second MOS tube, for controlling the on-off state of the second MOS tube V2.

[0054] Further, the cooperation of the current detection comparator module and the voltage comparator module can also meet the needs of low-power and high-power applications. Specifically, in a low-power scenario, since the input current is small, the current detection comparator module samples the current through the third resistor R1. Since the resistance value of the third resistor R1 is large, the sampling voltage is high, which can provide higher sampling accuracy. High-precision current detection ensures that the control of the input current is more accurate in low-power applications, which can improve the overall efficiency of the product. In a high-power scenario, the input current is large, and the current detection comparator module samples the current through the parallel connection of the third resistor R1 and the fourth resistor R2. Since the total resistance value of the third resistor R1 and the fourth resistor R2 in parallel connection is small, it can withstand a larger input current.

[0055] In an embodiment, the output end of the first comparator N2 is connected with the gate of the first MOS tube V1 through the latch RS1, and specifically comprises: the output end of the first comparator N2 is connected with the reset end of the latch RS1; and the output end of the latch RS1 is connected with the gate of the first MOS tube V1.

[0056] In the embodiment of the utility model, the first comparator N2 compares the voltage signals received by the non-inverted input end and the inverted input end, and when the voltage signal received by the non-inverted input end is higher than the voltage signal received by the inverted input end, the first comparator N2 outputs a high level signal, so that the latch RS1 latches the high level and drives the first MOS tube V1 to turn on.

[0057] As an optimization of the embodiment of the utility model, the utility model also provides a switching power supply, which comprises the PWM control circuit under the current mode.

[0058] Further, as another optimization of the embodiment of the utility model, the utility model also provides an electronic device, which comprises the switching power supply.

[0059] The embodiment of the utility model provides a PWM control circuit under the current mode, the current change of the primary winding is converted into the voltage signal of the secondary winding by the mutual inductor, the voltage signal is compared with the reference signal by the current detection comparator module, and the accurate current feedback signal is generated. Through the mutual inductor and the current detection comparator module, the circuit can accurately detect the change of the load current. And the use of the mutual inductor and the current detection comparator module replaces the large resistance resistor, and avoids the high power consumption and heating problem caused by the large resistance resistor. The actual output voltage is compared with the expected value by the error amplifier module, and the error signal is generated. The error signal is compared with the output signal of the current detection comparator module by the first comparator, and the accurate control signal is generated. Through the error amplifier module and the first comparator, the circuit can accurately control the output voltage. The output signal of the first comparator is latched by the latch, and the stable control signal is generated for controlling the turn-on and turn-off of the first MOS tube, so that the accuracy of current control is always kept at a high level under different load conditions. The voltage of the primary winding is converted into the voltage signal of the secondary winding by the transformer, the voltage signal is compared with the reference signal by the voltage comparator module, and the accurate control signal is generated, which controls the turn-on and turn-off of the second MOS tube. Through the transformer and the voltage comparator module, the circuit can efficiently transmit energy.

[0060] The above are only preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and substitutions can be made, and these improvements and substitutions should also be considered as the protection scope of the present application.

Claims

1. A PWM control circuit in current mode, characterized by The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit.

2. The current-mode PWM control circuit according to claim 1, wherein The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit.

3. The current-mode PWM control circuit according to claim 1, wherein The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit.

4. The current-mode PWM control circuit according to claim 1, wherein The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit.

5. The current-mode PWM control circuit according to claim 1, wherein, The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application relates to a current and voltage sampling circuit. The application 6. A switching power supply, characterized by comprising: A PWM control circuit in a current mode including any one of claims 1 to 5.

7. An electronic device, comprising: A switching power supply including the PWM control circuit according to claim 6.

Images