CXLE87210 is a four channel LED constant current driver IC based on power CMOS technology, which integrates MCU firmware, single wire digital interface, data latch, and LED constant current driver circuit internally. Its VDD pin is equipped with a built-in 5V voltage regulator, supporting a wide voltage input range of 6-24V, with simplified peripheral components and high system integration, suitable for various RGBW LED decorative lighting systems.
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[ CXLE87210 ]"
CXLE87210 Four channel LEDconstant current driveIC: High speed, high consistency lighting control solution
In the field of LED decorative lighting, the performance of the driver IC directly affects the systemstableSex and display effects.CXLE87210 is a four channel LED decoration product designed specifically for guardrail tubes, point light sources, and other LED decorative productsconstant current driveChip, integrated with high precisionPWM dimmingHigh speed data communication andstableWith advanced features such as constant current output, it has become the preferred chip for many lighting solutions. This article will comprehensively analyzeCXLE8721The technical characteristics, working principles, and typical applications of 0 help engineers achieve more efficient and reliable LED control system design.
1、 Product Introduction
CXLE87210 is a four channel LED based on power CMOS technologyconstant current driveIC， Internally integrated MCU firmware, single wire digital interface, data latch, and LEDconstant current driveCircuit. Its VDD pin is equipped with a built-in 5V voltage regulator, supporting 6-24VWide voltage inputWith streamlined peripheral components and high system integration, it is suitable for various RGBW LED decorative lighting systems.
2、 Core functional features
• High voltage resistant designThe OUT port has a voltage resistance of 32V and is suitable for various LED series configurations.
• Wide input voltage rangeVDD has a built-in 5V voltage regulator and supports 6-24V input after connecting resistors in series.
• Fixed current outputEach channel has a constant current output of 18mA, with high consistency.
• 256 levelsPWM dimming: Supports high precisionBrightness adjustmentSmooth and flicker free.
• High precision outputChannel error≤± 3%, inter chip error; 5%.
• Single line serial cascadeSupports infinite cascading, automatic signal shaping, and no attenuation.
• High speed communicationThe data transmission rate reaches 800KHz, with a higher refresh rate.
• Built in power on resetThe system initialization is reliable, and it defaults to the off state when powered on.
• SOP8 encapsulationSmall size, easy to integrate and dissipate heat.
3、 Pin definition and electrical characteristics
CXLE87210 adopts SOP8 packaging, and the pin definitions are as follows:
| Pin name | serial number | direction | Instructions |
|---|---|---|---|
| DIN | six | I | Serial data input |
| DO | five | O | Serial data output |
| VDD | seven | P | positive power terminal |
| OUTR | one | O | Red channel output |
| OUTG | two | O | Green channel output |
| OUTB | three | O | Blue channel output |
| OUTW | eight | O | White channel output |
| GND | four | P | power ground |
The working voltage range of the chip is 4.5V to 6.5V, with a static current as low as 0.5mA and a power consumption of only 250mW, demonstrating excellent energy efficiency performance.
4、 Communication Protocol and Data Format
CXLE87210 adoptionUnipolar zeroing codeCommunication protocol, supporting high speedstableSingle line serial data transmission. Each frame of data is set by multiple sets of 32-bit PWM setting commands (D1… Dn) and low power
Composed of a flat and effective reset signal.
The format of Dn data for each group is as follows:
| channel | data bit | Dimming level | Instructions |
|---|---|---|---|
| R | R[7:0] | 256 levels | Control the duty cycle of OUTR |
| G | G[7:0] | 256 levels | Control the duty cycle of OUTG |
| B | B[7:0] | 256 levels | Control the duty cycle of OUTB |
| W | W[7:0] | 256 levels | Control the duty cycle of OUTW |
The chip automatically forwards subsequent data after receiving 32-bit data, achieving seamless cascading. When the reset signal arrives, each chip converts the currently cached data into PWM output to achieve synchronous refresh.
5、 TypicalApplication Circuitdesign
5.1. Power configuration suggestions
CXLE87210 supports external power supply of 6-24V, and a current limiting resistor needs to be connected in series between the power supply and VDD. The calculation formula is as follows:
The commonly used configurations are as follows:
|
power supply voltage |
Serial resistance value |
|---|---|
|
5V |
No resistance required |
|
6V |
50Ω |
|
9V |
350Ω |
|
12V |
650Ω |
|
24V |
1.8kΩ |
5.2. Signal protection design
To prevent chip damage caused by live plugging and unplugging, it is recommended to connect 100Ω in series with DIN and DO pins; Resistors should be connected in parallel with 104 capacitors between VDD and GND of each chip, and decoupling capacitors should be placed as close as possible to the chip pin layout.
5.3. Constant current optimization suggestions
To maintain optimal performance, it is recommended to control the OUT port voltage between 1.2V and 3V. Excessive voltage will increase power consumption and temperature rise, affecting the lifespan of the system.
According to the constant current curve, when the OUT port voltage reaches 0.8V, it will enter a constant current state. But it's not that the higher the voltage, the better,
The higher the power consumption of the chip, the more severe the heat generation, which reduces the reliability of the entire system. It is recommended that the voltage be between 1.2-3V when the OUT port is open
For suitability, the excessive voltage at the OUT port can be reduced by connecting resistors in series.
5.4. Expansion application
If a larger driving current is required, the four ports OUTR, OUTG, OUTB, and OUTW can be short circuited for use, with a maximum output current of 72mA. The software needs to synchronously configure four sets of PWM registers to ensure consistent output.
6、 Refresh rate calculation and system performance
The system refresh rate is directly related to the number of cascaded pixels. Taking 800KHz communication rate as an example:
• Each pixel has a transmission time of 32 bits× 1.25μs = 40μ s
• If the system contains 1000 pixels, the total refresh time is 40ms, and the refresh rate is about 25Hz
The following table shows the refresh rate reference for different cascading points:
| Pixel count | Refresh time (ms) | Refresh rate (Hz) |
|---|---|---|
| 1~400 | sixteen | sixty-two point five |
| 1~800 | thirty-two | thirty-one point two five |
| 1~1000 | forty | twenty-five |
7、 Constant current characteristics and output curve
CXLE87210 has excellent constant current characteristics, entering a constant current state when the OUT port voltage reaches 0.8V. As shown in the following figure, the output current remains high within the load voltage range of 1.2V to 5VstableEnsure consistent LED brightness and system reliability.
! [Constant current curve graph]
8、 Encapsulation information
CXLE87210 adopts standard SOP8 packaging, with a size of 5.10mm× 4.00mm， The pin spacing is 1.27mm, suitable for automated surface mount and high-density PCB layout.
9、 Selection suggestion:CXLE87210 vsCXLE87211B
|
feature |
CXLE87211B |
|
|---|---|---|
|
output current |
Fixed 18mA |
6.5– 38mA adjustable |
|
dimming method |
256 level PWM |
256 level PWM+64 level constant current |
|
Communication speed |
800KHz |
400KHz |
|
data protocol |
Return-to-zero code |
Return to one code |
|
Reset level |
Low level effective |
active high |
|
Applicable scenarios |
High speed refresh, fixed current |
High requirements for current regulation and color accuracy |
10、 Conclusion
CXLE8721With its high-speed communication, high consistency output, and simple system design, 0 has become an ideal driving solution in the field of LED decorative lighting. Whether it's guardrail tubes, point light sources, or other RGBW lighting systems, this chip can providestableEfficient performance support.
To obtainCXLE87210 samples, technical data or procurement information, welcome to visitJTM-IC official websiteWe are committed to providing customers with original authentic products, technical support, and one-stop integrated circuit solutions to help your project succeed.
This article was written by the JTM-IC technical team. Please indicate the source when reprintingjtm-ic.com.
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