A programming control circuit for an LED driving circuit

Abstract

The utility model provides a kind of programming control circuit of LED drive circuit, it includes: direct current-direct current conversion circuit, input end is connected with input power end, output end is connected with output power end, feedback end receives feedback voltage;Control circuit, its first output end exports first control signal, second output end exports second control signal;Voltage feedback circuit, when first control signal is effective and second control signal is invalid, voltage feedback circuit provides first feedback voltage for direct current-direct current conversion circuit feedback end;When first control signal is invalid and second control signal is effective, voltage feedback circuit provides second feedback voltage for direct current-direct current conversion circuit feedback end;LED drive circuit, it is used to drive LED normal work or carry out programming operation.Compared with prior art, when the utility model needs to carry out programming operation in LED drive circuit, control DCDC output second output power voltage, and after programming operation is completed, control DCDC output first output power voltage.

Description

[Technical Field]

[0001] This utility model relates to the field of circuit design technology, and in particular to a programming control circuit for an LED driver circuit. [Background Technology]

[0002] The AS1163 is a mixed-signal device from ams OSRAM optimized for dynamic lighting applications. It supports the Open Systems Protocol (OSP) and its basic purpose is to drive nine LEDs arranged in a 3-channel triplet (RGB) configuration with independent pulse width modulation (PWM) dimming capabilities.

[0003] Due to the unique characteristics of the AS1163 chip, it requires an operating voltage of 4.3–5.5V during normal operation. However, during the One-Time Programmable Memory (OTP) process, the supply voltage needs to be reduced to 2.7V. This necessitates controlling the power supply of the SA1163 chip to achieve voltage conversion and meet the application requirements.

[0004] Therefore, it is necessary to propose a new technical solution to address the above problems. [Utility Model Content]

[0005] One of the objectives of this utility model is to provide a programming control circuit for an LED driver circuit. When the LED driver circuit needs to be programmed, the DC-DC converter is controlled to output a second output power supply voltage to realize the programming operation of the LED driver circuit. After the programming operation is completed, the DC-DC converter is controlled to output a first output power supply voltage to realize the normal operation of the LED driver circuit.

[0006] According to one aspect of the present invention, a programming control circuit for an LED driver circuit is provided, comprising: a DC-DC conversion circuit, wherein its input terminal is connected to an input power supply terminal VIN, its output terminal is connected to an output power supply terminal VOUT, and its feedback terminal FB receives a feedback voltage VFB; the DC-DC conversion circuit converts the input DC voltage into DC voltage outputs of different voltage levels based on the feedback voltage VFB; a control circuit, wherein its first output terminal outputs a first control signal Control-1, and its second output terminal outputs a second control signal Control-2; and a voltage feedback circuit, wherein when the first control signal Control-1 is valid and... When the second control signal Control-2 is invalid, the voltage feedback circuit provides a first feedback voltage VFB1 to the feedback terminal FB of the DC-DC conversion circuit; when the first control signal Control-1 is invalid and the second control signal Control-2 is valid, the voltage feedback circuit provides a second feedback voltage VFB2 to the feedback terminal FB of the DC-DC conversion circuit; the LED driver circuit has its power supply terminal connected to the output power supply terminal VOUT, its drive output terminal connected to the LED, and its communication terminal connected to the control circuit. The LED driver circuit is used to drive the LED to work normally or enter the programming mode and perform programming operations.

[0007] Compared with the prior art, this utility model controls the DC-DC converter to output a second output power supply voltage when the LED driver circuit needs to be programmed, so as to realize the programming operation of the LED driver circuit. After the programming operation is completed, it controls the DC-DC converter to output a first output power supply voltage, so as to realize the normal operation of the LED driver circuit. [Attached Image Description]

[0008] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0009] Figure 1 This is a circuit diagram of the programming control circuit of the LED driving circuit in one embodiment of the present invention.

Detailed Implementation Methods

[0010] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0011] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. Unless otherwise specified, the terms coupling, connection, linking, and interconnection used herein to indicate electrical connection mean direct or indirect connection. For example, A being connected to B includes both a direct electrical connection between A and B and a connection between A and B via electrical components or circuits.

[0012] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "back", "positive", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0013] Please refer to Figure 1 As shown, it is a circuit diagram of the programming control circuit of the LED driving circuit in one embodiment of the present invention. Figure 1 The programming control circuit of the LED driver circuit shown includes a DC-DC converter circuit (i.e., DCDC) 110, a control circuit (i.e., MCU) 120, a voltage feedback circuit 130, and an LED driver circuit 140.

[0014] The DC-DC converter circuit 110 has its input terminal connected to the input power supply terminal VIN, its output terminal connected to the output power supply terminal VOUT, and its feedback terminal FB receiving a feedback voltage VFB. Based on the feedback voltage VFB, the DC-DC converter circuit 110 converts the input DC voltage into DC voltages of different voltage levels for output. The control circuit 120 outputs a first control signal Control-1 at its first output terminal and a second control signal Control-2 at its second output terminal. When the first control signal Control-1 is valid and the second control signal Control-2 is invalid, the voltage feedback circuit 130 provides a first feedback voltage VFB1 to the feedback terminal FB of the DC-DC converter circuit 110; when the first control signal Control-1 is invalid and the second control signal Control-2 is valid, the voltage feedback circuit 130 provides a second feedback voltage VFB2 to the feedback terminal FB of the DC-DC converter circuit 110. The LED driver circuit 140 has its power supply terminal connected to the output power supply terminal VOUT, its driver output terminal connected to the LED, and its communication terminal connected to the control circuit 120. The LED driver circuit 140 is used to drive the LED to work normally or to enter programming mode and perform programming operations.

[0015] When the first control signal Control-1 is valid and the second control signal Control-2 is invalid, the voltage feedback circuit 130 provides a first feedback voltage VFB1 to the feedback terminal FB of the DC-DC converter circuit 110. The DC-DC converter circuit 110 outputs a first output power supply voltage VOUT1 based on the first feedback voltage VFB1. At this time, the LED driver circuit 140 drives the LED to work normally. When the first control signal Control-1 is invalid and the second control signal Control-2 is valid, the voltage feedback circuit 130 provides a second feedback voltage VFB2 to the feedback terminal FB of the DC-DC converter circuit 110. The DC-DC converter circuit 110 outputs a second output power supply voltage VOUT2 based on the second feedback voltage VFB2. At this time, the LED driver circuit 140 enters the programming mode, and the control circuit 120 performs programming operations on the LED driver circuit 140. In this mode, the first output power supply voltage VOUT1 is greater than the second output power supply voltage VOUT2.

[0016] When programming is required, the LED driver circuit 140 sends a first instruction to the control circuit 120. After receiving the first instruction, the control circuit 120 outputs a first control signal Control-1 that is invalid and a second control signal Control-2 that is valid. At this time, the voltage feedback circuit 130 provides a second feedback voltage VFB2 to the feedback terminal FB of the DC-DC converter circuit 110. The DC-DC converter circuit 110 outputs a second output power supply voltage VOUT2 based on the second feedback voltage VFB2. After programming is completed, the LED driver circuit 140 sends a second instruction to the control circuit 120. After receiving the second instruction, the control circuit 120 outputs a first control signal Control-1 that is valid and a second control signal Control-2 that is invalid. At this time, the voltage feedback circuit 130 provides a first feedback voltage VFB1 to the feedback terminal FB of the DC-DC converter circuit 110. The DC-DC converter circuit 110 outputs a first output power supply voltage VOUT1 based on the first feedback voltage VFB1.

[0017] exist Figure 1 In the specific embodiment shown, the voltage feedback circuit 130 includes resistors R1, R2, and R3, and switching transistors Q1 and Q2. One end of resistor R1 is connected to the output power supply terminal VOUT, and the other end is connected to node A. Node A is connected to the feedback terminal FB of the DC-DC conversion circuit 110. The first connection terminal of switching transistor Q1 is connected to node A, and its second connection terminal is grounded through resistor R2. Its control terminal is connected to the first output terminal of the control circuit 120. The first connection terminal of switching transistor Q2 is connected to node A, and its other end is grounded through resistor R3. Its control terminal is connected to the second output terminal of the control circuit 120. The voltage at node A is the feedback voltage VFB output by the voltage feedback circuit 130.

[0018] exist Figure 1 In the specific embodiment shown, switch Q1 is an NMOS transistor, and the first connection terminal, the second connection terminal, and the control terminal of switch Q1 are the drain, source, and gate of the NMOS transistor, respectively; switch Q2 is an NMOS transistor, and the first connection terminal, the second connection terminal, and the control terminal of switch Q2 are the drain, source, and gate of the NMOS transistor, respectively.

[0019] When the first control signal Control-1 is valid (e.g., the first control signal Control-1 is high) and the second control signal Control-2 is invalid (e.g., the second control signal Control-2 is low), the switch Q1 is turned on and the switch Q2 is turned off. Resistors R1 and R2 are connected in series between the output power supply terminal VOUT and the ground terminal. The voltage feedback circuit 130 provides the first feedback voltage VFB1 to the feedback terminal FB of the DC-DC conversion circuit 110. At this time, the DC-DC conversion circuit 110 outputs the first output power supply voltage VOUT1 based on the first feedback voltage VFB1. The voltage value of VOUT1 is set relatively high (e.g., to meet the power supply voltage required for the normal operation of the LED driver circuit 140 (e.g., 4.3 to 5.5V)).

[0020] When the first control signal Control-1 is invalid (e.g., the first control signal Control-1 is low) and the second control signal Control-2 is valid (e.g., the second control signal Control-2 is high), the switch Q1 is turned off and the switch Q2 is turned on. Resistors R1 and R3 are connected in series between the output power supply terminal VOUT and the ground terminal. The voltage feedback circuit 130 provides the second feedback voltage VFB2 to the feedback terminal FB of the DC-DC conversion circuit 110. At this time, the DC-DC conversion circuit 110 outputs the second output power supply voltage VOUT2 based on the second feedback voltage VFB2. The voltage value of VOUT2 is set to be low (e.g., just enough to meet the power supply voltage required by the LED driver circuit 140 for programming operations (e.g., 2.7V)).

[0021] Figure 1 The programming control circuit of the LED driver circuit shown also includes a filter circuit 150, which is connected between the output terminal of the DC-DC converter circuit 110 and the output power supply terminal VOUT. The filter circuit 150 is a filter circuit for the output power supply terminal VOUT, which reduces the ripple of the output voltage of the DC-DC converter circuit 110 and is an unavoidable part in the circuit design. Figure 1 In the specific embodiment shown, the filter circuit 150 includes an inductor L1 and a capacitor C2. One end of the inductor L1 is connected to the output terminal of the DC-DC conversion circuit 110, and the other end is connected to the output power supply terminal VOUT. One end of the capacitor C2 is connected to the output power supply terminal VOUT, and the other end is grounded. In other embodiments, the filter circuit 150 may also be other filter circuits including capacitors.

[0022] Figure 1The programming control circuit of the LED driver circuit shown also includes a low-dropout linear regulator (LDO) 150 and a capacitor C1. The input terminal of the LDO 150 is connected to the input power supply terminal VIN, and its output terminal is connected to the power supply terminal of the control circuit 120. The LDO 150 is used to convert an unstable input voltage into a stable output voltage. One end of the capacitor C1 is connected to the input power supply terminal VIN, and the other end is grounded. The capacitor C1 serves as the input filter capacitor for both the DC-DC converter and the LDO.

[0023] exist Figure 1 In the illustrated embodiment, the LED driving circuit 140 includes multiple cascaded LED driving chips. The control circuit 120 is communicatively connected to the communication terminal of the first LED driving chip. The two cascaded LED driving chips are interconnected through their communication terminals. The driving output terminals of some or all of the LED driving chips are connected to the corresponding LEDs. The power supply terminal of each LED driving chip is connected to the output power supply terminal VOUT. The LED driving chip is a one-time programmable LED driving chip. After entering the programming mode, the control circuit 120 programs each LED driving chip to configure the address of each LED driving chip.

[0024] exist Figure 1 In the specific embodiment shown, the LED driver chip is an AS1163 chip; the programming operation is an OTP write to the AS1163 chip; the AS1163 chip writes the corresponding address through OTP (One Time Programmable) to drive the LED; the control circuit 120 communicates with the first AS1163 chip through SPI (Serial Peripheral Interface); the two cascaded AS1163 chips communicate through LVDS (Low-Voltage Differential Signaling).

[0025] exist Figure 1 In the specific embodiment shown, the LED driving circuit 140 includes multiple cascaded AS1163 chips, namely AS1163-0, AS1163-1, AS1163-2, ..., AS1163-X. The control circuit 120 communicates with AS1163-0 via SPI, and the cascaded AS1163 chips communicate via LVDS. AS1163-0 serves as the first address bit determination circuit, the driving output terminal of AS1163-1 is connected to LED1, the driving output terminal of AS1163-2 is connected to LED2, ..., and the driving output terminal of AS1163-X is connected to LEDX.

[0026] The control circuit 120 (i.e., the MCU) communicates with AS1163-0 via SPI. AS1163-0 is the first address bit, and whether the first address needs to be configured can be determined according to the actual application. AS1163-0 communicates with AS1163-1, AS1163-2 to AS1163-X via LVDS signals. AS1163-1, AS1163-2 to AS1163-X can be configured with different addresses to drive LEDs. According to the characteristics of AS1163, a maximum of 1028 addresses can be configured, that is, the maximum value of X is 1028.

[0027] During normal operation, the control circuit 120 (i.e., the MCU) controls Control_1 to output a high level and Control_2 to output a low level. At this time, MOSFET Q1 is turned on and Q2 is turned off. By selecting and matching resistors R1 and R2, the DC-DC converter circuit (i.e., DCDC) 110 can output 5V, and the circuit system can operate normally. When an OTP write operation is required, the control circuit 120 (i.e., the MCU) receives a command and controls Control_1 to output a low level and Control_2 to output a high level. At this time, MOSFET Q1 is turned off and Q2 is turned on. By selecting and matching resistors R1 and R3, the DC-DC converter circuit (i.e., DCDC) 110 can output 2.7V, powering the AS1163 for the OTP write operation. After the OTP write operation is completed, the control circuit 120 (i.e., the MCU) receives a command and controls Control_1 to output a high level and Control_2 to output a low level, making the DC-DC converter circuit (i.e., DCDC) 110 output 5V, and the circuit system can operate normally. In other words, Figure 1 The programming control circuit of the LED driver circuit shown controls the DC-DC converter (DC-DC converter) to reduce the original 5V supply voltage to 2.7V when the AS1163 chip needs to perform OTP, so as to realize the OTP write operation of the AS1163 chip. After the OTP write operation is completed, the 2.7V voltage is raised to 5V so that the AS1163 chip can work normally.

[0028] In summary, when the LED driver circuit needs to be programmed, this utility model controls the DC-DC converter (i.e., DC-DC converter) to output a second output power supply voltage to realize the programming operation of the LED driver circuit. After the programming operation is completed, it controls the DC-DC converter (i.e., DC-DC converter) to output a first output power supply voltage to realize the normal operation of the LED driver circuit.

[0029] It should be noted that any modifications made by those skilled in the art to the specific embodiments of this utility model do not depart from the scope of the claims of this utility model. Accordingly, the scope of the claims of this utility model is not limited to the foregoing specific embodiments.

Claims

1. A programming control circuit for an LED driver circuit, characterized in that, It includes: A DC-DC converter circuit has its input terminal connected to the input power supply terminal VIN, its output terminal connected to the output power supply terminal VOUT, and its feedback terminal FB receiving a feedback voltage VFB. The DC-DC converter circuit converts the input DC voltage into DC voltage outputs of different voltage levels based on the feedback voltage VFB. The control circuit outputs a first control signal Control-1 at its first output terminal and a second control signal Control-2 at its second output terminal. The voltage feedback circuit provides a first feedback voltage VFB1 to the feedback terminal FB of the DC-DC converter when the first control signal Control-1 is valid and the second control signal Control-2 is invalid; and provides a second feedback voltage VFB2 to the feedback terminal FB of the DC-DC converter when the first control signal Control-1 is invalid and the second control signal Control-2 is valid. The LED driver circuit has its power supply terminal connected to the output power supply terminal VOUT, its drive output terminal connected to the LED, and its communication terminal connected to the control circuit. The LED driver circuit is used to drive the LED to work normally or enter the programming mode and perform programming operations.

2. The programming control circuit for the LED driver circuit according to claim 1, characterized in that, When the voltage feedback circuit provides a first feedback voltage VFB1 to the feedback terminal FB of the DC-DC converter circuit, the DC-DC converter circuit outputs a first output power supply voltage VOUT1 based on the first feedback voltage VFB1. At this time, the LED driver circuit drives the LED to work normally. When the voltage feedback circuit provides a second feedback voltage VFB2 to the feedback terminal FB of the DC-DC converter circuit, the DC-DC converter circuit outputs a second output power supply voltage VOUT2 based on the second feedback voltage VFB2. At this time, the LED driver circuit enters programming mode, and the control circuit performs programming operations on the LED driver circuit. Wherein, the first output power supply voltage VOUT1 is greater than the second output power supply voltage VOUT2.

3. The programming control circuit for the LED driver circuit according to claim 2, characterized in that, When programming is required, the LED driver circuit sends a first instruction to the control circuit. After receiving the first instruction, the first control signal Control-1 output by the control circuit is invalid and the second control signal Control-2 is valid. At this time, the voltage feedback circuit provides a second feedback voltage VFB2 to the feedback terminal FB of the DC-DC conversion circuit. After the programming operation is completed, the LED driving circuit sends a second instruction to the control circuit. After receiving the second instruction, the control circuit outputs the first control signal Control-1 as valid and the second control signal Control-2 as invalid. At this time, the voltage feedback circuit provides the first feedback voltage VFB1 to the feedback terminal FB of the DC-DC conversion circuit.

4. The programming control circuit for the LED driver circuit according to claim 3, characterized in that, The voltage feedback circuit includes resistors R1, R2, and R3, and switching transistors Q1 and Q2. One end of resistor R1 is connected to the output power supply terminal VOUT, and the other end is connected to node A. Node A is connected to the feedback terminal FB of the DC-DC conversion circuit. The first connection terminal of switch Q1 is connected to node A, and its second connection terminal is grounded through resistor R2. Its control terminal is connected to the first output terminal of the control circuit. The first connection terminal of switch Q2 is connected to node A, and the other end is grounded through resistor R3. Its control terminal is connected to the second output terminal of the control circuit. The voltage at node A is the feedback voltage VFB output by the voltage feedback circuit.

5. The programming control circuit for the LED driver circuit according to claim 4, characterized in that, When the first control signal Control-1 is valid and the second control signal Control-2 is invalid, the switch Q1 is turned on and the switch Q2 is turned off. When the first control signal Control-1 is invalid and the second control signal Control-2 is valid, the switch Q1 is turned off and the switch Q2 is turned on.

6. The programming control circuit for the LED driver circuit according to claim 5, characterized in that, The switching transistor Q1 is an NMOS transistor, and the first connection terminal, the second connection terminal, and the control terminal of the switching transistor Q1 are the drain, source, and gate of the NMOS transistor, respectively. The switch Q2 is an NMOS transistor, and the first connection terminal, the second connection terminal, and the control terminal of the switch Q2 are the drain, source, and gate of the NMOS transistor, respectively.

7. The programming control circuit for the LED driver circuit according to claim 6, characterized in that, It also includes a filter circuit. The filter circuit includes an inductor L1 and a capacitor C2. One end of the inductor L1 is connected to the output terminal of the DC-DC conversion circuit, and the other end is connected to the output power supply terminal VOUT. One end of the capacitor C2 is connected to the output power supply terminal VOUT, and the other end is grounded.

8. The programming control circuit for the LED driver circuit according to any one of claims 1-7, characterized in that, The LED driving circuit includes multiple cascaded LED driving chips. The control circuit is communicatively connected to the communication terminal of the first LED driving chip. The two cascaded LED driving chips are interconnected through their communication terminals. The driving output terminals of some or all of the LED driving chips are connected to the corresponding LEDs. The power supply terminal of each LED driver chip is connected to the output power supply terminal VOUT; The LED driver chip is a one-time programmable LED driver chip. After entering programming mode, the control circuit programs each LED driver chip to configure the address of each LED driver chip.

9. The programming control circuit for the LED driver circuit according to claim 8, characterized in that, The LED driver chip is an AS1163 chip. The programming operation is the OTP write to the AS1163 chip. The AS1163 chip drives the LED by writing the corresponding address via OTP.

10. The programming control circuit for the LED driving circuit according to claim 9, characterized in that, The first AS1163 chip serves as the first address bit determination circuit, and the drive output terminals of the remaining AS1163 chips are connected to the corresponding LEDs.

Images