Power converter and switching power supply device

Patent metadata

Field	Value
Publication number	US-9985525-B2
Application number	US-201615317126-A
Country	US
Kind code	B2
Filing date	Jan 28, 2016
Priority date	Jul 7, 2015
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

The present disclosure discloses a power converter and a switching power supply device. The power converter includes an energy storing and outputting circuit used for charging a load after storing energy, a main switch used for transmitting input power to the energy storing and outputting circuit when the main switch is conducting, an after flow switch used for supplying an after flow loop to the energy storing and outputting circuit when the main switch is shut down, a driving circuit used for changing connecting states of the main switch and the after flow switch according to a preset clock frequency, and a testing circuit and a feedback circuit, the testing circuit is used for testing a voltage on a connecting node of the main switch and the after flow switch.

First claim

What is claimed is:

1. A power converter, comprising: a main switch and an after flow switch connected in series between a power supply and ground, an energy storing and outputting circuit connected with a connecting node of the main switch and the after flow switch, a driving circuit changing connecting states of the main switch and the after flow switch according to a preset clock frequency, when the main switch being conducting, the energy storing and outputting circuit being in an energy-storing state and an outputting state; when the after flow switch being conducting, the energy storing and outputting circuit being in the outputting state; when the energy storing and outputting circuit being in the outputting state, the energy storing and outputting circuit supplying a working voltage to a load;
the power converter comprising a testing circuit and a feedback circuit, a signal acquiring end of the testing circuit being connected with the connecting mode of the main switch and the after flow switch, an outputting end of the testing circuit being connected with the driving circuit; a signal acquiring end of the feedback circuit being connected with an outputting end of the energy-storing circuit, an outputting end of the feedback circuit being connected with a feedback end of the driving circuit;
the testing circuit, which being used for testing a voltage on the connecting node of the main switch and the after flow switch, when the voltage on the connecting node being larger than zero, the testing circuit outputting a first controlling signal to the driving circuit, allowing the driving circuit controlling the after flow switch to change from the conducting state to a shutting down state, and the load working normally through the voltage stored in the energy storing and outputting circuit;
the feedback circuit, which being used for testing the voltage stored in the energy storing and outputting circuit, and when the voltage stored in the energy storing and outputting circuit being smaller than a first preset voltage value, the feedback circuit outputting a trigger signal to the driving circuit, allowing the driving circuit controlling the main switch to change from the shutting down state to the conducting state, and the energy-storing device being charged again;
wherein the driving circuit comprises a controller, a PWM controlling circuit and a logic circuit; the PWM controlling circuit comprises a first end inputting a first reference voltage signal, a second end inputting a second reference voltage signal; the logic circuit comprises a first end connected with an outputting end of the PWM controlling circuit, and a second end used for receiving the first controlling signal, a third end used for inputting a preset clock frequency and an outputting end; the outputting end of the logic circuit is connected with the controller; when a feedback of the feedback circuit is that the voltage stored in the energy storing and outputting circuit is smaller than the first preset voltage value, the PWM controlling circuit is used for outputting a second trigger signal, after the second trigger signal is logically treated, the logically treated second trigger signal is sent to the controller, for the controller controlling the main switch to change from the shutting down state to the conducting state, the energy storing and outputting circuit is charged again; and
wherein the PWM controlling circuit comprises an error amplifier and a first voltage comparator; the logic circuit comprises a first nand gate, a second nand gate, a first inverter and a first trigger; a non-inverting inputting end of the error amplifier inputs the first reference voltage signal, a non-inverting inputting end of the first voltage comparator inputs the second reference voltage signal, a clock inputting end of the first trigger inputs the preset clock frequency signal; the controller comprises a first driving pin, a second driving pin, a first inputting pin and a second inputting pin, the first driving pin is connected with a controlled end of the main switch, the second driving pin of the controller is connected with a controlled end of the after flow switch, the first inputting pin of the controller is connected with an outputting end of the first trigger, a second inputting pin of the controller is connected with the outputting end of the testing circuit; a inverting inputting end of the error amplifier is the feedback end of the driving circuit, an outputting end of the error amplifier is connected with a inverting inputting end of the first voltage comparator; an outputting end of the first voltage comparator is connected with a first inputting end of the first nand gate, a second inputting end of the first nand gate is connected with an outputting end of the second nand gate, an outputting end of the first nand gate is connected with a trigger end of the first trigger through the first inverter; a first inputting end of the second nand gate is connected with an outputting end of the first trigger, a second inputting end of the second nand gate is connected with the outputting end of the testing circuit.

2. The power converter according to claim 1 , wherein the load comprises a power supply end and a ground end, the power supply end is connected with the outputting end of the energy storing and outputting circuit, the ground end of the load is earthed; the energy storing and outputting circuit comprises a first inductor and a first capacitor, an inputting end of the first inductor is connected with the connecting node of the main switch and the after flow switch, an outputting end of the first inductor is connected with a first end of the first capacitor, and one end of the outputting end of the first inductor connected with the first end of the capacitor is the outputting end of the energy-storing outputting circuit; a second end of the first capacitor is earthed.

3. The power converter according to claim 1 , wherein the feedback circuit comprises a first resistor and a second resistor, a first end of the first resistor is connected between the outputting end of the energy storing and outputting circuit and the power supply end of the load, a second end of the first resistor is earthed through the second resistor; a connecting node of the first resistor and the second resistor is the outputting end of the feedback circuit.

4. The power converter according to claim 1 , wherein the driving circuit further comprises a current sampling module, a first sampling end of the current sampling module is connected with the inputting end of the main switch, a second sampling end of the current sampling module is connected with the outputting end of the main switch; the current sampling module samples current signals of the inputting end and the outputting end of the main switch, and outputs voltage signals corresponding to the current signals; an non-inverting inputting end of the first voltage comparator is connected with the outputting end of the current sampling module, for receiving the voltage signal outputted by the current sampling module, and the voltage signal is regarded as the second reference voltage signal.

5. The power converter according to claim 1 , wherein the testing circuit comprises a first direct-current power supply, a first switch testing device, a current mirroring circuit, a first sampling circuit, a second sampling circuit, a comparing outputting circuit, the current mirroring circuit comprises a starting end, an inputting end, a first outputting end, a second outputting end, the starting end of the current mirroring circuit is connected with an external power, the inputting end of the current mirroring circuit is connected with the first direct current power supply, the first outputting end of the current mirroring circuit is connected with the first samp

Assignees

• Shenzhen Skyworth Rgb Electronics Co Ltd
• Shenzhen Skyworth Semiconductor Design Center Co Ltd

Inventors

• Zuo Shijun
• Chen Lu
• Teng Mouyan

Classifications

• H02M1/08

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title

• H02M2001/0009

  Electricity · mapped topic

• H02M3/158 Primary

  including plural semiconductor devices as final control devices for a single load · CPC title

• H02M3/1588 Primary

  comprising at least one synchronous rectifier element (H02M3/1582, H02M3/1584 take precedence) · CPC title

• H02M1/0054

  Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035) · CPC title