• [ CXLE87190 ]"

Ordering

CXLE87190: Deep Analysis of High Performance 18 Channel Constant Current LED Driver Chip

          In today's LED lighting and control applications, precise current control and flexible color adjustment have become the key to design. CXLE87190, as a constant current LED driver chip with 128 order linear current regulation function, is widely used in fields such as breathing lamps, RGB dimming, and intelligent lighting due to its excellent performance and rich control functions. This article will provide a comprehensive analysis of the technical features, working principles, register configuration, and practical applications of CXLE87190, providing engineers with a comprehensive reference.Huj嘉泰姆

1、 Chip Overview

        CXLE87190 is an LED driver circuit that integrates 18 independent constant current output channels. Each output current can be precisely adjusted within the range of 3mA to 40mA. This chip adopts the I2C bus communication protocol and supports four chip selection addresses, making it suitable for complex systems where multiple devices work together. Its unique 128 level current fine-tuning function (adjustment range 0%~190%) makes it perform excellently in scenarios such as color gradients and smooth brightness adjustment.Huj嘉泰姆

2、 Main characteristics

•       18 constant current outputsEach output current has high accuracy, and the difference between channels is less than or equal to; 1.5%, inter chip differences<± 3%.Huj嘉泰姆

•       128 level current regulationSupports wide range current fine-tuning from 0% to 190%, suitable for fine brightness control.Huj嘉泰姆

•       I2C control interfaceSupports standard I2C communication, with 4 configurable chip addresses for easy system expansion.Huj嘉泰姆

•       RGB grouping controlEvery three LED channels share an enable switch, which enables independent dimming and color mixing of RGB light groups.Huj嘉泰姆

•       Soft shutdown functionSupport software controlled shutdown to reduce static power consumption.Huj嘉泰姆

•       Wide voltage operationCompatible with 3.3V and 5V systems, suitable for various application scenarios.Huj嘉泰姆

•       package formProvide QSOP24 and QFN24 packaging options to meet different space and heat dissipation requirements.Huj嘉泰姆

3、 Pin and electrical characteristics

          The pin layout of CXLE87190 is simple and clear, mainly including power supply (VDD, GND), I2C interface (SCL, SDA), external resistance adjustment terminal (REXT), address selection (ADDR), and 18 output ports (OUT0~OUT17). Its electrical characteristics are as follows:Huj嘉泰姆

•       Working voltage range：2.4V~5.5VHuj嘉泰姆

•       Output current range：3mA~40mAHuj嘉泰姆

•       Current accuracyTypical errors between channels± 1.5%, typical inter chip error± 3%Huj嘉泰姆

•       temperature range-40 ℃ to+85 ℃, suitable for industrial grade environmentsHuj嘉泰姆
3.1.    Extreme working conditionsHuj嘉泰姆
Huj嘉泰姆
(1) Long term operation of chips under the above extreme parameter conditions may cause a decrease in device reliability or permanent damage, and Tian Microelectronics does not buildHuj嘉泰姆
When any parameter reaches or exceeds these limit values in actual use.Huj嘉泰姆
(2) All voltage values are tested relative to the system ground.Huj嘉泰姆
3.2.    Recommended working conditionsHuj嘉泰姆
Huj嘉泰姆
3.3.    DC electrical characteristicsHuj嘉泰姆
Huj嘉泰姆
Huj嘉泰姆
3.4.      AC communication characteristicsHuj嘉泰姆
Huj嘉泰姆
Note: Cb=total capacitance of PF.Huj嘉泰姆

4、 I2C Communication and Register Configuration

CXLE87190 implements all control functions, including brightness settings, switch control, and mode selection, through the I2C interface. Its register structure is clear, mainly including:Huj嘉泰姆

•       RSTCTR register (00h)Used for soft turn off control.Huj嘉泰姆

•       RGB-OE register (01h)Control the enable status of 6 sets of RGB lights.Huj嘉泰姆

•       FIXBRIT_LED0~LED17 registers (02h~13h)Set fixed brightness values for 18 LED channels, each supporting 128 levels of adjustment.Huj嘉泰姆

By configuring these registers, users can achieve various functions such as single lamp dimming, group control color adjustment, global switch, etc., to meet the needs of complex lighting scenes.Huj嘉泰姆
4.1.      I2C data transmission time waveform:Huj嘉泰姆
Huj嘉泰姆
4.2.     I2C bus description:Huj嘉泰姆

(1) Bus interface: MCU transmits data to CXLE87190 through SDA and SCL ports. SDA and SCL form the bus interface. needHuj嘉泰姆
Connect a pull-up resistor to the power supply terminal.Huj嘉泰姆
(2) Data validity: When the SCL signal is at a high level, the data on the SDA port is valid and stable. Only when the SCL signal is presentHuj嘉泰姆
Only when the level is low can the level on the SDA port be changed.Huj嘉泰姆
(3) Start (restart) and stop working conditions: when SCL  The signal is at a high level, and the SDA signal switches from a high level to a low level to start workingHuj嘉泰姆
When the SCL signal is at a high level and the SDA signal transitions from a low level to a high level, the work stops or resumes.Huj嘉泰姆
(4) Byte format: Each byte of the data line consists of 8 bits. Each byte contains a response bit. The first data transmitted is MSB.Huj嘉泰姆
(5) Response: During the response clock period, the host keeps the SDA port at a high level. During write mode, CXLE87190 will send a response signal toHuj嘉泰姆
The SDA port is at a low level during the response period.Huj嘉泰姆
Huj嘉泰姆
(6) Chip address: CXLE87190 has four types of chip addresses that can be used, as shown in the table belowHuj嘉泰姆
Huj嘉泰姆
(7) I2C Interface Protocol: Write Command Register Interface Protocol (Continuous Write)Huj嘉泰姆
Huj嘉泰姆
◆ Starting positionHuj嘉泰姆
◆ Chip slave address byte=01000110bHuj嘉泰姆
◆ ACK=Response bitHuj嘉泰姆
Register address byte=address (xxx+register 5-bit address)Huj嘉泰姆
◆ ACK=Response bitHuj嘉泰姆
Command register data 1=(command data bit cmd1)Huj嘉泰姆
◆ ACK=Response bitHuj嘉泰姆
Command register data 2=(command data bit cmd2)Huj嘉泰姆
◆ ACK=Response bitHuj嘉泰姆
◆… … … … …Huj嘉泰姆
Command register data n=(command data bit cmdn)Huj嘉泰姆
◆ ACK=Response bitHuj嘉泰姆
◆ Stop positionHuj嘉泰姆

4.3.      Register definition:Huj嘉泰姆

Huj嘉泰姆
Huj嘉泰姆
Note: (1) After setting the fixed brightness (current) value of each LED light, the switch signal of the LED enable register can be used to adjust itHuj嘉泰姆
The brightness and darkness changes of RGBin lights, with n ranging from 0 to>5. Please refer to the application circuit diagram for the RGB light group lighting method.Huj嘉泰姆
(2) After turning on all LED switches, change the fixed brightness (constant current) of each LED lamp in the fixed brightness (constant current) registerHuj嘉泰姆
The constant current value can adjust the brightness change of a single LED light.Huj嘉泰姆
Fixed brightness (constant current) registerHuj嘉泰姆
Huj嘉泰姆

5、 Current regulation mechanism

The current regulation of CXLE87190 is divided into two levels:Huj嘉泰姆

5.1.  Basic current settingThe basic output current is set through the external resistor REXT, and the calculation formula is:Huj嘉泰姆

Among them, R− EXT=1.24V. For example, when Rext=1240Ω   At this time, the base current is 12.5mA.Huj嘉泰姆
VR-EXT in the formula refers to the voltage value at the R-EXT terminal, while Rext refers to the resistance value externally connected to the R-EXT terminal. When the resistance value is 1240 ohms,Huj嘉泰姆
The output current value obtained by inserting the formula is 12.5mA (typical value).Huj嘉泰姆
5.2.    Current gain adjustment (fixbrit_ledn [6:0]):Huj嘉泰姆
The default value is 0000000 (the current gain is relative to 1010010)Huj嘉泰姆
The range of low current mode is from 0% to 64%, with a total of 65 stages.Huj嘉泰姆
The high current mode range is from 1000001 to 1111111, with a current range of 66% to 190%, and a total of 63 stages.Huj嘉泰姆
The current calculation formula is (note: D is the value converted from the lower 6 digits of the current adjustment value to decimal):Huj嘉泰姆
Low current mode: gain=D/100Huj嘉泰姆
High current mode: gain=(2D+64)/100Huj嘉泰姆
The following figure shows the current situation in two modes:Huj嘉泰姆
Huj嘉泰姆

5.3.    Digital dimmingThrough the FIXBRIT register, 128 order current fine-tuning is achieved, which is divided into low current mode (0%~64%) and high current mode (66%~190%), corresponding to different gain calculation formulas, ensuring smooth adjustment throughout the entire range.Huj嘉泰姆

6、 Typical Application Circuit

          CXLE87190 can be widely used in smart homes, car lighting, advertising screens, stage lighting and other fields. Its typical application circuit is simple, requiring only a small number of peripheral components (such as REXT resistors and decoupling capacitors) to operate stably. Supports parallel use of multiple chips, suitable for large-scale LED matrix control.Huj嘉泰姆

The reference application circuit is as follows:Huj嘉泰姆
Huj嘉泰姆

7、 Packaging and Size

        The chip offers two packaging forms, QSOP24 and QFN24, with compact size suitable for high-density PCB layout. QFN packaging has good heat dissipation performance and is suitable for high current driving scenarios.Huj嘉泰姆

8、 Conclusion

          CXLE87190 has become a star product in the LED driver market due to its advantages of high precision, multi-channel, and flexible dimming. Whether it's a simple breathing light design or a complex full-color RGB system, it can provide stable and reliable solutions. If you are looking for a high-performance and flexible LED driver chip, CXLE87190 would be your ideal choice.Huj嘉泰姆

9Selection Guide for Related Chips;                          More similar products ....Huj嘉泰姆

◀ Previous:CXLE87189 Single Line Three Channel LED Driver Chip | 65536 Level Brightness | Dual Channel Cascade | JTM-IC

Back to top

Next▶:CXLE87191 18 channel LED driver chip -256 level PWM dimming QFN-24/SOP-24 package | Jiataim Semiconductor