WO2020087864A1

WO2020087864A1 - Low-power consumption fast startup circuit for led driving power source

Info

Publication number: WO2020087864A1
Application number: PCT/CN2019/080862
Authority: WO
Inventors: 祁振立; 邹超洋
Original assignee: 深圳市崧盛电子股份有限公司
Priority date: 2018-11-01
Filing date: 2019-04-01
Publication date: 2020-05-07
Also published as: CN209419941U

Abstract

A Low-power consumption fast startup circuit for an LED driving power source. In the present startup circuit, an input end of an input rectifier circuit (10) is connected to an AC power source, and an output end of the input rectifier circuit is connected to a fast startup circuit (30) by means of a filter circuit (20). An output end of the fast startup circuit is connected to a PWM control chip (50); an output end of an auxiliary winding power supply circuit (40) is connected to the fast startup circuit; and an output end of the auxiliary winding power supply circuit is connected to the PWM control chip. The fast startup circuit is added to the periphery of a control chip without a high-voltage startup circuit to turn off, after the LED driving power source is quickly started up, the power supply to a PWM control chip by a bus voltage obtained by rectifying a power source input, so that the loss on the power supply line of the PWM control chip by the bus voltage can be significantly reduced, and the efficiency of the power source can be improved, thereby improving the reliability of the power supply and extending the service life of the LED driving power source.

Description

A low-power fast startup circuit for LED drive power

Technical field

The utility model relates to the field of LED power supplies, and more particularly, to a low-power fast startup circuit for LED drive power supplies.

Background technique

With the improvement of people's living standards, people's requirements for quality of life are getting higher and higher. As far as LED lighting is concerned, people hope that LED lighting fixtures that can save energy and turn on quickly appear in life. However, in the current LED lighting market, there are still many ways to turn on the drive power supply, which are connected between the input rectifier and the VCC power supply pin of the PWM control chip through several large resistance resistors, and directly supply high voltage power to the PWM control chip. There are not many chips, which leads to the fact that there are still many LED lighting fixtures on the market that have been turned on for a little longer, which has become more and more unsatisfactory, and now some technical standards have clearly required standby power consumption to be less than 0.5W. The startup time is less than 0.75S, so a new startup method is urgently needed to meet the above requirements.

technical problem

The technical problem to be solved by the utility model is to provide a low-power fast-start circuit for LED driving power supply in view of the above-mentioned defects of the prior art.

Technical solution

The technical scheme adopted by the utility model to solve its technical problems is to construct a low-power fast startup circuit for LED drive power, including an input rectifier circuit, a filter circuit, a fast startup circuit, an auxiliary winding power supply circuit, and a PWM control chip, in which ,

The input end of the input rectification circuit is connected to an AC power source, the output end of the input rectification circuit is connected to the quick start circuit through the filter circuit, and the output end of the fast start circuit is connected to the PWM control chip;

The output terminal of the auxiliary winding power supply circuit is connected to the quick start circuit, and the output terminal of the auxiliary winding power supply circuit is connected to the PWM control chip.

Further, in the low-power fast start-up circuit of the LED driving power supply according to the present invention, the input rectifier circuit is a diode group rectifier circuit.

Further, in the low-power fast startup circuit of the LED driving power supply according to the present invention, the filter circuit is a capacitor C1, one end of the capacitor C1 is connected to the output end of the input rectifier circuit, and the other end of the capacitor C1 One end is grounded.

Further, the low-power fast startup circuit of the LED driving power supply according to the present invention includes a reference voltage stabilizing circuit, a MOS transistor Q1, a transistor Q2, a voltage divider circuit, and a capacitor CE1, wherein,

The input end of the reference voltage stabilizing circuit is connected to the connection point of the capacitor C1 and the input rectifier circuit, and the output end of the reference voltage stabilizing circuit is respectively connected to the gate of the MOS transistor Q1 and the collector of the triode Q2 , The grounding terminal of the reference voltage stabilizing circuit is grounded;

The drain of the MOS tube Q1 is connected to the connection point of the capacitor C1 and the input rectifier circuit, the source of the MOS tube Q1 is connected to one end of the capacitor CE1, and the other end of the capacitor CE1 is grounded;

The base of the transistor Q2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1 through a voltage dividing circuit;

The PWM control chip connects the connection point of the capacitor CE1 and the MOS transistor Q1.

Further, in the low-power fast startup circuit of the LED driving power supply according to the present invention, the reference voltage stabilizing circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a three-terminal regulator U3;

The input end of the three-terminal regulator U3 is connected to the connection point of the capacitor C1 and the input rectifier circuit through the series connection of the resistor R1 and the resistor R2;

The output terminal of the three-terminal regulator U3 is connected to the gate of the MOS transistor Q1 and the collector of the transistor Q2 through the resistor R3; the output terminal of the three-terminal regulator U3 passes through the resistor R4 is connected to the emitter of the transistor Q2;

The ground terminal of the three-terminal regulator U3 is grounded.

Further, the low power consumption fast startup circuit of the LED driving power supply according to the present invention, the voltage dividing circuit includes a resistor R7 and a resistor R8;

The base of the transistor Q2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1 through the resistor R7, and the base of the transistor Q2 is connected to the emitter of the transistor Q2 through the resistor R8.

Further, the low-power fast-start circuit of the LED driving power supply according to the present invention, the fast-start circuit further includes a resistor R5 and a diode D1;

The drain of the MOS tube Q1 is connected to the connection point of the capacitor C1 and the input rectifier circuit through the resistor R5; the source of the MOS tube Q1 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected The capacitor CE1.

Further, the low-power fast startup circuit of the LED driving power supply according to the present invention, the fast startup circuit further includes a resistor R6, and the gate of the MOS transistor Q1 is connected to the MOS transistor Q1 through the resistor R6 Source.

Further, in the low-power fast startup circuit of the LED driving power supply according to the present invention, the auxiliary winding power supply circuit includes a transformer auxiliary winding, a resistor R9, and a diode D2;

The auxiliary winding of the transformer is connected to the anode of the diode D2 through a resistor R9, and the cathode of the diode D2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1;

The cathode of the diode D2 is connected to the PWM control chip.

Further, in the low-power fast startup circuit of the LED driving power supply according to the present invention, the capacitor CE1 is an electrolytic capacitor, the positive electrode of the electrolytic capacitor is connected to the source electrode of the MOS tube Q1, and the negative electrode of the electrolytic capacitor Ground.

Beneficial effect

The low-power fast start-up circuit of an LED driving power supply implementing the present invention has the following beneficial effects: the start-up circuit includes an input rectifier circuit, a filter circuit, a fast start-up circuit, an auxiliary winding power supply circuit, and a PWM control chip, in which the input The input end of the rectifier circuit is connected to an AC power supply, the output end of the input rectifier circuit is connected to a fast start circuit through a filter circuit, and the output end of the fast start circuit is connected to a PWM control chip; The output terminal is connected to the PWM control chip. The utility model adds a quick start circuit to the periphery of the control chip without high-voltage startup, so that the LED drive power supply is quickly started to disconnect the power supply and the rectified bus voltage supplies power to the PWM control chip, and the bus voltage is significantly reduced to power the PWM control chip The loss on the line improves the power supply efficiency, thereby improving the reliability of the power supply and extending the service life of the LED drive power supply.

BRIEF DESCRIPTION

The utility model will be further described below with reference to the drawings and embodiments. In the drawings:

1 is a schematic structural view of a low-power fast startup circuit for an LED driving power supply of the present invention;

FIG. 2 is a circuit diagram of a low-power fast startup circuit of an LED driving power supply of the present invention.

Best Mode of the Invention

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation of the present invention will now be described in detail with reference to the drawings.

Referring to FIG. 1, the present utility model constructs a low-power fast-start circuit for LED driving power, including an input rectifier circuit 10, a filter circuit 20, a fast-start circuit 30, an auxiliary winding power supply circuit 40, and a PWM control chip 50, wherein, The input end of the input rectification circuit 10 is connected to an AC power source, and the output end of the input rectification circuit 10 is connected to the quick start circuit 30 through the filter circuit 20, and the output end of the fast start circuit 30 is connected to the PWM control chip 50. The output end of the auxiliary winding power supply circuit 40 is connected to the quick start circuit 30, and the output end of the auxiliary winding power supply circuit 40 is connected to the PWM control chip 50.

The working mode of the quick start circuit is: the input rectifier circuit 10 and the filter circuit 20 rectify the input AC signal of the LED drive power into a DC signal, and the quick start circuit 30 quickly transfers the input rectified signal to the VCC power supply pin of the PWM control chip 50 , So that the PWM control chip 50 is quickly turned on and outputs a driving signal to drive the main switch tube of the LED power supply to work, so that the power supply is turned on. Then the auxiliary winding power supply circuit 40 obtains energy and supplies power to the VCC of the PWM control chip 50, and then the quick start circuit 30 cuts off the connection between the input rectified signal and the VCC pin of the PWM control chip 50, and thereafter the auxiliary winding power supply circuit 40 The PWM control chip 50 will be powered until the LED drive power is turned off, and the above process is repeated after starting again.

The above working mode will significantly reduce the energy consumption of the starting resistor after the LED driving power supply works, improve the efficiency of the power supply and realize a quick start.

Referring to FIG. 2, the low-power fast-start circuit of the LED driving power supply of the present invention, the input rectifier circuit 10 is a diode group rectifier circuit. The rectifier circuit of the diode group can refer to the prior art, and is not repeated here.

Further, in the low-power fast startup circuit of the LED driving power supply of the present invention, the filter circuit 20 is a capacitor C1, one end of the capacitor C1 is connected to the output end of the input rectifier circuit 10, and the other end of the capacitor C1 is grounded.

Further, the low-power fast startup circuit of the LED driving power supply of the present invention, the quick startup circuit 30 includes a reference voltage stabilizing circuit, a MOS transistor Q1, a transistor Q2, a voltage dividing circuit, and a capacitor CE1, wherein the reference voltage stabilizing circuit The input end is connected to the connection point of the capacitor C1 and the input rectifier circuit 10, the output end of the reference voltage stabilizing circuit is connected to the gate of the MOS transistor Q1 and the collector of the transistor Q2, respectively, and the ground end of the reference voltage stabilizing circuit is grounded.

The drain of the MOS tube Q1 is connected to the connection point of the capacitor C1 and the input rectifier circuit 10, the source of the MOS tube Q1 is connected to one end of the capacitor CE1, and the other end of the capacitor CE1 is grounded;

The PWM control chip 50 connects the connection point of the capacitor CE1 and the MOS transistor Q1.

Further, the low-power fast startup circuit of the LED driving power supply of the present invention, the reference voltage stabilizing circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a three-terminal regulator U3;

The input end of the three-terminal regulator U3 is connected to the connection point of the input rectifier circuit 10 through a series resistor R1 and a resistor R2 connected to the capacitor C1;

The output terminal of the three-terminal regulator U3 is connected to the gate of the MOS transistor Q1 and the collector of the transistor Q2 through the resistor R3; the output terminal of the three-terminal regulator U3 is connected to the emitter of the transistor Q2 through the resistor R4;

The ground terminal of the three-terminal regulator U3 is grounded.

Further, the low power consumption fast startup circuit of the LED driving power supply of the present invention, the voltage dividing circuit includes a resistor R7 and a resistor R8; the base of the transistor Q2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1 through the resistor R7, The base is connected to the emitter of transistor Q2 through resistor R8.

Further, the low-power fast startup circuit of the LED driving power supply of the present invention, the fast startup circuit 30 further includes a resistor R5 and a diode D1; the drain of the MOS tube Q1 is connected to the connection point of the input rectifier circuit 10 through the resistor R5 and the capacitor C1; The source of the MOS transistor Q1 is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the capacitor CE1. The base of the transistor Q2 is connected to the negative connection point of the capacitor CE1 and the diode D1 through the resistor R7.

Further, the low-power fast startup circuit of the LED driving power supply of the present invention, the quick startup circuit 30 further includes a resistor R6, and the gate of the MOS transistor Q1 is connected to the source of the MOS transistor Q1 through the resistor R6.

Further, the low power consumption fast start circuit of the LED driving power supply of the present invention, the auxiliary winding power supply circuit 40 includes a transformer auxiliary winding, a resistor R9, and a diode D2;

The auxiliary winding of the transformer is connected to the anode of the diode D2 through the resistor R9, and the cathode of the diode D2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1;

The cathode of the diode D2 is connected to the PWM control chip 50.

Further, in the low-power fast start-up circuit of the LED driving power supply of the present invention, the capacitor CE1 is an electrolytic capacitor, the positive electrode of the electrolytic capacitor is connected to the source of the MOS tube Q1, and the negative electrode of the electrolytic capacitor is grounded.

Specifically, the working process of the low-power fast-start circuit of the LED driving power supply is as follows:

When the LED drive power supply is energized, the power supply rectifier bridge, BD1, rectifies the input AC signal, and then the capacitor C1 filters the rectified signal to obtain the bus voltage VBUS, resistance R1, resistance R2, resistance R3, resistance R4, The reference voltage stabilizing circuit composed of the three-terminal regulator U3 provides a stable and reliable driving signal to the MOS tube Q1, so that the MOS tube Q1 is reliably turned on. Then the bus voltage VBUS charges the capacitor CE1 through the resistor R5, the MOS transistor Q1, and the diode D1. Because the value of resistor R5 is small, the capacitor CE1 can be quickly charged. When the voltage on the capacitor CE1 reaches the starting voltage of the PWM control chip, U2, the PWM control chip U2 outputs a drive signal to drive the main MOS tube to work. Then the auxiliary winding obtains energy, and after current limiting by resistor R9, diode D2 is rectified, the VCC pin of PWM control chip U2 is powered to charge CE1; at the same time, resistor R7 and resistor R8 divide the voltage on capacitor CE1. The signal is transferred to the base of the transistor Q2, which turns on the transistor Q2, the gate of the MOS transistor Q1 is connected to the reference ground, the gate of the MOS transistor Q1 is low, and the MOS transistor Q1 is turned off, resulting in the bus voltage VBUS and PWM control The VCC power supply pin of chip U2 is disconnected. After that, the PWM control chip U2 only supplies power through the auxiliary winding, which avoids the situation that the LED drive power supply is simultaneously powered by the bus voltage VBUS and the auxiliary winding to the PWM control chip U2, reducing energy loss and improving power supply efficiency. When the LED drive power is turned on again after being powered off, repeat the above process.

The utility model adds a quick start circuit to the periphery of the control chip without high-voltage startup, so that the LED drive power supply is quickly started to disconnect the power supply and the rectified bus voltage supplies power to the PWM control chip, and the bus voltage is significantly reduced to power the PWM control chip The loss on the line improves the power supply efficiency, thereby improving the reliability of the power supply and extending the service life of the LED drive power supply.

The above embodiments are only for explaining the technical concept and features of the present invention. The purpose is to allow those familiar with the technology to understand the contents of the present invention and implement them accordingly, without limiting the scope of protection of the present invention. Any changes and modifications made within the scope of the claims of the present invention shall fall within the scope of the claims of the present invention.

Claims

A low-power fast-start circuit for LED drive power, characterized in that it includes an input rectifier circuit (10), a filter circuit (20), a fast-start circuit (30), an auxiliary winding power supply circuit (40), and a PWM control chip ( 50), where,

The input terminal of the input rectifier circuit (10) is connected to an AC power source, and the output terminal of the input rectifier circuit (10) is connected to the fast start circuit (30) through the filter circuit (20), and the fast start circuit ( 30) The output terminal is connected to the PWM control chip (50);

The output terminal of the auxiliary winding power supply circuit (40) is connected to the quick start circuit (30), and the output terminal of the auxiliary winding power supply circuit (40) is connected to the PWM control chip (50).
The low power consumption fast startup circuit of the LED driving power supply according to claim 1, wherein the input rectification circuit (10) is a diode group rectification circuit.
The low-power fast startup circuit of the LED driving power supply according to claim 1, wherein the filter circuit (20) is a capacitor C1, and one end of the capacitor C1 is connected to the output of the input rectifier circuit (10) End, the other end of the capacitor C1 is grounded.
The low-power fast-start circuit of the LED driving power supply according to claim 3, characterized in that the fast-start circuit (30) includes a reference voltage stabilizing circuit, a MOS transistor Q1, a transistor Q2, a voltage divider circuit, and a capacitor CE1 ,among them,

The input end of the reference voltage stabilizing circuit is connected to the connection point of the capacitor C1 and the input rectifier circuit (10), and the output end of the reference voltage stabilizing circuit is respectively connected to the gate of the MOS transistor Q1 and the transistor Q2 Of the collector, the ground terminal of the reference voltage stabilizing circuit is grounded;

The drain of the MOS tube Q1 is connected to the connection point of the capacitor C1 and the input rectifier circuit (10), the source of the MOS tube Q1 is connected to one end of the capacitor CE1, and the other end of the capacitor CE1 is grounded;

The base of the transistor Q2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1 through a voltage dividing circuit;

The PWM control chip (50) connects the connection point of the capacitor CE1 and the MOS transistor Q1.
The low-power fast-start circuit of the LED driving power supply according to claim 4, wherein the reference voltage stabilizing circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, and a three-terminal regulator U3;

The input end of the three-terminal regulator U3 is connected to the connection point of the capacitor C1 and the input rectifier circuit (10) through the series connection of the resistor R1 and the resistor R2;

The output terminal of the three-terminal regulator U3 is connected to the gate of the MOS transistor Q1 and the collector of the transistor Q2 through the resistor R3; the output terminal of the three-terminal regulator U3 passes through the resistor R4 is connected to the emitter of the transistor Q2;

The ground terminal of the three-terminal regulator U3 is grounded.
The low power consumption fast startup circuit of the LED driving power supply according to claim 5, wherein the voltage dividing circuit includes a resistor R7 and a resistor R8;

The base of the transistor Q2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1 through the resistor R7, and the base of the transistor Q2 is connected to the emitter of the transistor Q2 through the resistor R8.
The low power consumption fast start circuit of the LED driving power supply according to claim 6, characterized in that the fast start circuit (30) further includes a resistor R5 and a diode D1;

The drain of the MOS tube Q1 is connected to the connection point of the capacitor C1 and the input rectifier circuit (10) through the resistor R5; the source of the MOS tube Q1 is connected to the anode of the diode D1, and the diode D1 Is connected to the capacitor CE1.
The low-power fast-start circuit of the LED driving power supply according to claim 7, wherein the fast-start circuit (30) further includes a resistor R6, and the gate of the MOS transistor Q1 is connected to the gate through the resistor R6 Describe the source of the MOS transistor Q1.
The low-power fast startup circuit of the LED driving power supply according to claim 4, wherein the auxiliary winding power supply circuit (40) includes a transformer auxiliary winding, a resistor R9, and a diode D2;

The auxiliary winding of the transformer is connected to the anode of the diode D2 through a resistor R9, and the cathode of the diode D2 is connected to the connection point of the capacitor CE1 and the MOS transistor Q1;

The cathode of the diode D2 is connected to the PWM control chip (50).
The low-power fast startup circuit of the LED driving power supply according to claim 4, wherein the capacitor CE1 is an electrolytic capacitor, the positive electrode of the electrolytic capacitor is connected to the source of the MOS transistor Q1, and the electrolytic capacitor The negative pole of the is grounded.