CN218830706U

CN218830706U - LED drive control circuit

Info

Publication number: CN218830706U
Application number: CN202222618958.XU
Authority: CN
Inventors: 陈致祥
Original assignee: Zhongshan Zhongai Electronic Technology Co ltd
Current assignee: Zhongshan Zhongai Electronic Technology Co ltd
Priority date: 2022-09-29
Filing date: 2022-09-29
Publication date: 2023-04-07
Anticipated expiration: 2032-09-29

Abstract

The utility model discloses a LED drive control circuit, include: a first LED light source and a second LED light source; the brush type direct current motor driving chip U1 comprises a first input end, a second input end, a first output end, a second output end, an undervoltage locking end and an overcurrent protection end; one end of the current limiting resistor is electrically connected with the overcurrent protection end, and the other end of the current limiting resistor is grounded; one end of the filtering unit and one end of the power supply unit are respectively and electrically connected with the under-voltage locking end, and the other end of the filtering unit and the other end of the power supply are respectively grounded; by adopting the brush type direct current motor driving chip, the driving control of the LED can be realized, the circuit is greatly simplified, under-voltage locking protection, short-circuit protection and thermal shutdown can be provided without complex peripheral circuits, and the cost is saved.

Description

LED drive control circuit

Technical Field

The utility model relates to a LED illumination field, especially a LED drive control circuit.

Background

The existing LED driving control circuit generally adopts discrete electronic components, such as two pairs of N-MOS transistors + P-MOS transistors, two half-bridge chips and a plurality of N-MOS transistors to form a control circuit, where the two half-bridge chips are a main control unit to output a control signal, the control signal passes through the two pairs of N-MOS transistors + P-MOS transistors to generate a driving signal with a certain duty ratio, and the driving signal passes through the N-MOS transistors to drive the corresponding LEDs to operate; the drive control circuit has no protection function, and can realize undervoltage protection, overcurrent protection and the like only by adding a large number of peripheral devices, so that the whole circuit structure is complex and the cost is high.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to solve one of the technical problem that exists among the prior art at least, provide one kind and can simplify circuit and reduce cost's LED drive control circuit.

According to the utility model discloses LED drive control circuit, include: a first LED light source and a second LED light source; the brush type direct current motor driving chip U1 comprises a first input end, a second input end, a first output end, a second output end, an under-voltage locking end and an over-current protection end, wherein external PWM signals can be input into the first input end and the second input end respectively, the first output end is electrically connected with the anode of the first LED light source and the cathode of the second LED light source respectively, and the second output end is electrically connected with the anode of the second LED light source and the cathode of the first LED light source respectively; one end of the current limiting resistor is electrically connected with the overcurrent protection end, and the other end of the current limiting resistor is grounded; the power supply comprises a filtering unit and a power supply unit, wherein one end of the filtering unit and one end of the power supply unit are respectively electrically connected with the under-voltage locking end, and the other end of the filtering unit and the other end of the power supply are respectively grounded.

According to the utility model discloses LED drive control circuit has following beneficial effect at least: an H-bridge driving circuit is integrated in the brush type direct current motor driving chip U1, the input ends of the H-bridge driving circuit are a first input end and a second input end, the output ends of the H-bridge driving circuit are a first output end and a second output end, the H-bridge driving circuit can drive a first LED lamp source and a second LED lamp source to work, an under-voltage locking protection circuit, a short-circuit protection circuit and an over-temperature turn-off circuit are further integrated in the brush type direct current motor driving chip, and when the voltage of the under-voltage locking end is lower than the under-voltage locking threshold voltage, the internal H-bridge driving circuit is stopped outputting; when the voltage of the under-voltage locking end is higher than the threshold voltage, the circuit automatically restores to normal work; when the output current exceeds the OCP threshold value of the chip, the internal H-bridge driving circuit stops outputting; when the internal junction temperature of the chip exceeds a certain safety limit, the internal H-bridge driving circuit stops outputting, and after the temperature of the chip is reduced to a safety level, the circuit automatically restores to normal work; therefore, the driving control of the LED can be realized by adopting the brush type direct current motor driving chip, the circuit is greatly simplified, under-voltage locking protection, short-circuit protection and thermal shutoff can be provided without a complex peripheral circuit, and the cost is saved.

According to the utility model discloses LED drive control circuit, brush direct current motor driver chip U1 is the DRV8872 chip, undervoltage locking end is the VM terminal, overcurrent protection end is the ISEN terminal, and DRV8872 chip has undervoltage locking protection, overcurrent protection and hot turn-off function, and the integrated level is high, the stable performance.

According to the utility model discloses LED drive control circuit, the filter unit includes resistance R1 and electric capacity C1, and resistance R1 and electric capacity C1 are parallelly connected to form parallel circuit, parallel circuit's one end respectively with the electrical unit with the VM terminal electricity of DRV8872 chip is connected, parallel circuit's other end ground connection, this filter circuit simple structure can carry out the filtering to the voltage of electrical unit output.

According to the utility model discloses LED drive control circuit, power supply unit includes rectifier circuit and transformer T1, rectifier circuit's input is connected with the external power supply electricity, rectifier circuit's output and transformer T1's once side electricity is connected, transformer T1's secondary side one end with parallel circuit's one end electricity is connected, the other end ground connection of transformer T1's secondary side, rectifier circuit carry out the rectification to the external power supply, and transformer T1 steps down, makes the suitable voltage of DRV8872 chip input.

According to the utility model discloses LED drive control circuit, first LED lamp source is including LED1 and the LED2 of establishing ties, second LED lamp source is including LED3 and the LED4 of establishing ties, LED 1's positive pole with LED 4's negative pole respectively with the first output electricity of DRV8872 chip is connected, LED 2's negative pole with LED 3's positive pole respectively with the second output electricity of DRV8872 chip is connected, when first input and second input alternate input high-low level, first output and second output alternate output high-low level to make first LED lamp source and second LED lamp source switch on in turn.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The following description will further describe embodiments of the present invention with reference to the accompanying drawings.

Fig. 1 is a circuit diagram of an LED drive control circuit.

Detailed Description

This section will describe in detail the embodiments of the present invention, preferred embodiments of the present invention are shown in the attached drawings, which are used to supplement the description of the text part of the specification with figures, so that one can intuitively and vividly understand each technical feature and the whole technical solution of the present invention, but they cannot be understood as the limitation of the protection scope of the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated with respect to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

Referring to fig. 1, an LED driving control circuit according to an embodiment of the present invention includes a first LED light source 11 and a second LED light source 12, a brush type dc motor driving chip U1, a current limiting resistor R2, a filtering unit 20, and a power supply unit 30, where the brush type dc motor driving chip U1 may be an AS4950 chip or a DRV8872 chip; IN some embodiments, the brush type dc motor driving chip U1 is a DRV8872 chip, an H-bridge driving circuit is integrated IN the DRV8872 chip, a first input end of the H-bridge driving circuit is an IN1 terminal, a second input end of the H-bridge driving circuit is an IN2 terminal, a first output end of the H-bridge driving circuit is an OUT1 terminal, and a second output end of the H-bridge driving circuit is an OUT2 terminal, the H-bridge driving circuit can drive the first LED light source 11 and the second LED light source 12 to operate, and an under-voltage locking protection circuit, a short-circuit protection circuit and an over-temperature turn-off circuit are further integrated IN the DRV8872 chip, wherein the under-voltage locking terminal is a VM terminal, the over-current protection terminal is an ISEN terminal, one end of the current limiting resistor R2 is electrically connected to the ISEN terminal, and the other end of the current limiting resistor R2 is grounded; when the voltage of the VM terminal is lower than the undervoltage locking threshold voltage, the internal H-bridge driving circuit stops outputting; when the voltage of the VM terminal is higher than the threshold voltage, the circuit automatically restores normal operation; when the output current exceeds the OCP threshold value of the chip, the internal H-bridge driving circuit stops outputting; when the internal junction temperature of the chip exceeds a certain safety limit, the internal H bridge driving circuit stops outputting, and after the temperature of the chip is reduced to a safety level, the circuit automatically restores to normal work. Therefore, the driving control of the LED can be realized by adopting the brush type direct current motor driving chip U1, the circuit is greatly simplified, under-voltage locking protection, short-circuit protection and thermal shutdown can be provided without a complex peripheral circuit, and the cost is saved.

The first LED lamp source 11 comprises an LED1 and an LED2 which are connected in series, the second LED lamp source 12 comprises an LED3 and an LED4 which are connected in series, the anode of the LED1 and the cathode of the LED4 are respectively and electrically connected with the OUT1 terminal of the DRV8872 chip, and the cathode of the LED2 and the anode of the LED3 are respectively and electrically connected with the OUT2 terminal of the DRV8872 chip; the IN1 terminal and the IN2 terminal can input external PWM signals, when the IN1 terminal inputs a high level and the IN2 terminal inputs a low level, the output current is from the OUT1 terminal to the OUT2 terminal, and the first LED light source 11 is turned on; when the IN2 terminal inputs a high level and the IN1 terminal inputs a low level, the output current is from the OUT2 terminal to the OUT1 terminal, and the second LED light source 12 is turned on; when the IN1 terminal and the IN2 terminal respectively input the PWM signal, the output current from the OUT1 terminal to the OUT2 terminal and the output current from the OUT2 terminal to the OUT1 terminal are rapidly alternated at high frequency, so that the first LED light source 11 and the second LED light source 12 are alternately turned on at high frequency, thereby operating simultaneously.

In some embodiments, the filtering unit 20 includes a resistor R1 and a capacitor C1, the resistor R1 and the capacitor C1 are connected in parallel to form a parallel circuit, one end of the parallel circuit is electrically connected to the power supply unit 30 and the VM terminal of the DRV8872 chip, respectively, and the other end of the parallel circuit is grounded, and the filtering circuit has a simple structure and can filter the voltage output by the power supply unit 30.

In some embodiments, the power supply unit 30 includes a rectifying circuit 31 and a transformer T1, the rectifying circuit 31 may be a bridge rectifying circuit 31, an input end of the rectifying circuit 31 is electrically connected to an external power supply, an output end of the rectifying circuit 31 is electrically connected to a primary side of the transformer T1, one end of a secondary side of the transformer T1 is electrically connected to one end of the parallel circuit, the other end of the secondary side of the transformer T1 is grounded, the rectifying circuit 31 rectifies the external power supply, and the transformer T1 steps down to enable the DRV8872 chip to input a proper voltage.

It is readily understood by those skilled in the art that the above-described preferred modes can be freely combined and superimposed without conflict.

The above is only the preferred embodiment of the present invention, not limiting the patent scope of the present invention, all of which are under the concept of the present invention, the equivalent structure transformation made by the contents of the specification and the drawings is utilized, or the direct or indirect application is included in other related technical fields in the patent protection scope of the present invention.

Claims

1. An LED drive control circuit, comprising:

a first LED light source (11) and a second LED light source (12);

the brush type direct current motor driving chip U1 comprises a first input end, a second input end, a first output end, a second output end, an under-voltage locking end and an over-current protection end, wherein external PWM signals can be input into the first input end and the second input end respectively, the first output end is electrically connected with the anode of the first LED light source (11) and the cathode of the second LED light source (12) respectively, and the second output end is electrically connected with the anode of the second LED light source (12) and the cathode of the first LED light source (11) respectively;

one end of the current limiting resistor is electrically connected with the overcurrent protection end, and the other end of the current limiting resistor is grounded;

the filter unit comprises a filter unit (20) and a power supply unit (30), one end of the filter unit (20) and one end of the power supply unit (30) are respectively electrically connected with the under-voltage locking end, and the other end of the filter unit (20) and the other end of the power supply are respectively grounded.

2. The LED driving control circuit of claim 1, wherein:

the brush type direct current motor driving chip U1 is a DRV8872 chip, the undervoltage locking end is a VM terminal, and the overcurrent protection end is an ISEN terminal.

3. The LED driving control circuit of claim 2, wherein:

the filtering unit (20) comprises a resistor R1 and a capacitor C1, the resistor R1 and the capacitor C1 are connected in parallel to form a parallel circuit, one end of the parallel circuit is electrically connected with the power supply unit (30) and the VM terminal of the DRV8872 chip respectively, and the other end of the parallel circuit is grounded.

4. The LED driving control circuit of claim 3, wherein:

the power supply unit (30) comprises a rectifying circuit (31) and a transformer T1, wherein the input end of the rectifying circuit (31) is electrically connected with an external power supply, the output end of the rectifying circuit (31) is electrically connected with the primary side of the transformer T1, one end of the secondary side of the transformer T1 is electrically connected with one end of the parallel circuit, and the other end of the secondary side of the transformer T1 is grounded.

5. The LED driving control circuit of claim 2, wherein:

the first LED lamp source (11) comprises an LED1 and an LED2 which are connected in series, the second LED lamp source (12) comprises an LED3 and an LED4 which are connected in series, the anode of the LED1 and the cathode of the LED4 are respectively and electrically connected with the first output end of the DRV8872 chip, and the cathode of the LED2 and the anode of the LED3 are respectively and electrically connected with the second output end of the DRV8872 chip.