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Comprehensive Analysis and Application Guide of CXLE88149B LED Driver Control Chip

1、 Chip Overview

        CXLE88149B is a control circuit chip designed specifically for LED display driver, which integrates MCU digital interface, data latch, LED driver circuit and other modules internally. This chip is manufactured using CMOS technology and has the characteristics of high reliability, low power consumption, and strong anti-interference ability. It is widely used in digital tube display driver scenarios for various electronic devices. Its packaging forms are SOP28 and SSOP28, suitable for high-density PCB layout requirements.Urb嘉泰姆

CXLE88149B supports 8 segments× 16 bit display mode with 8-level adjustable duty cycle precision adjustment function, can communicate with the main control MCU through two-wire serial interfaces (SCLK, DIN), built-in RC oscillator and power on reset circuit, greatly simplifying peripheral circuit design.Urb嘉泰姆

2、 Main characteristics

▲ Display capability: Supports up to 8 segments× 16 bit LED displayUrb嘉泰姆

▲ Communication interfaceTwo wire serial interface (SCLK, DIN), supporting high-speed data transmissionUrb嘉泰姆

▲ Precision adjustment8-level duty cycle adjustable to meet different brightness requirementsUrb嘉泰姆

▲ Built in oscillatorRC oscillation, no need for external crystal oscillatorUrb嘉泰姆

▲ Power ManagementBuilt in power on reset circuit, supporting a wide voltage range (3.0V~5.5V)Urb嘉泰姆

▲ Packaging options：SOP28、SSOP28， Suitable for different spatial layout requirementsUrb嘉泰姆

3、 Detailed explanation of pin functions

symbol

pin name

Pin number

Instructions

DIN

data input

seven

Serial data input, the input data changes at the low level of SCLK and is transmitted at the high level of SCLK.

SCLK

Clock input

eight

Input data on the rising edge

SEG1~SEG8

Output (segment)

9-16

Segment output, P-tube leakage output

GRID1~GRID11 GRID12~GRID16

Output (bit)

18-28Urb嘉泰姆 1-5

Bit output, N-tube open leak output

VDD

Logic power supply

seventeen

Connect the power supply positively

VSS

Logically speaking

six

Grounding system

▲ DIN (Pin 7)Serial data input, data changes at SCLK low level and latches at high levelUrb嘉泰姆

SCLK (pin 8)Clock input, rising edge triggers data transmissionUrb嘉泰姆

▲ SEG1~SEG8 (pins 9~16)Segment output, P-tube leakage outputUrb嘉泰姆

▲ GRID1~GRID16 (pins 1-5, 18~28)Bit output, N-tube open drain outputUrb嘉泰姆

▲ VDD (pin 17)Positive pole of logic power supplyUrb嘉泰姆

▲ VSS (Pin 6): Logically speakingUrb嘉泰姆

4、 Electrical parameters and working conditions

4.1. Limit parameter (Ta=25 ℃)

4.1.1) Logic power supply voltage: -0.5V~+7.0VUrb嘉泰姆

4.1.2) SEG foot pull current: 90mA (VDD=4.5~5.5V)Urb嘉泰姆

4.1.3) Grid foot current: 200mAUrb嘉泰姆

4.1.4) Working temperature: -40 ℃~+85 ℃Urb嘉泰姆

4.1.5）Storage temperature: -65 ℃~+150 ℃Urb嘉泰姆

4.2. Recommended working conditions (Ta=-40~+85 ℃, Vss = 0 V）

4.2.1) Power supply voltage: 3.0V~5.5VUrb嘉泰姆

4.2.2) High level input voltage: 0.7VDDUrb嘉泰姆

4.2.3）Low level input voltage: 0.3VDDUrb嘉泰姆

4.3. Electrical characteristics (Ta=-40~+85 ℃, VDD = 3.0 ～ 5.5 V， Vss = 0 V）

4.3.1）SEG output current: 55mA (typical value, Vo=VDD-2V）Urb嘉泰姆

4.3.2）GRID output current: 140mA (typical value, Vo=0.3V）Urb嘉泰姆

4.3.3）Dynamic current loss:<5mA (no load)Urb嘉泰姆

4.4. Switching characteristics (Ta =  -40 to+85 ℃, VDD   =   3.0   ～ 5.5   V）Urb嘉泰姆

4.5. Timing characteristics (Ta =  -40 to+85 ℃, VDD   =   3.0   ～ 5.5   V）Urb嘉泰姆

5、 Communication Protocol and Instruction Set

        The data of the microprocessor communicates with CXLE88149B through a two-wire bus interface. When CLK is at high level during data input, the signal on DINUrb嘉泰姆
Must remain unchanged; The signal on DIN can only change when the clock signal on CLK is low. The input of data is always low before highUrb嘉泰姆
Positioned after transmission The starting condition for data input is that when CLK is at a high level, DIN changes from high to low; The end condition is that CLK is high and DIN is lowUrb嘉泰姆
Change from flat to high level.Urb嘉泰姆
The process of instruction data transmission is shown in the following figure:Urb嘉泰姆
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5.1.1) Write SRAM data address auto increment mode:Urb嘉泰姆
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Command1: Set DataUrb嘉泰姆
Command2: Set AddressUrb嘉泰姆
Data1~N: Transfer display data (up to 16 bytes)Urb嘉泰姆
Command3: Control DisplayUrb嘉泰姆
5.1.2）Write SRAM data in fixed address mode:Urb嘉泰姆
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Command1: Set DataUrb嘉泰姆
Command2: Set AddressUrb嘉泰姆
Data1: Transfer display dataUrb嘉泰姆
CommandN: Set AddressUrb嘉泰姆
DataN: Transfer display data (up to 16 bytes)Urb嘉泰姆
Command3: Control Display

        CXLE88149B adopts a two-wire serial communication protocol, and the data transmission format isLow level firstThe starting condition for communication is that DIN changes from high to low when SCLK is high, and the ending condition is that DIN changes from low to high when SCLK is high.Urb嘉泰姆

5.2. Instruction classification (based on the highest two bits of bytes):

01: Data command settings (address automatically incremented by 1/fixed address)Urb嘉泰姆

tenDisplay control commands (switch display, pulse width adjustment)Urb嘉泰姆

Display address command settingsUrb嘉泰姆

When powered on, the address is set to C0H by default.Urb嘉泰姆
The correspondence between display data, chip pins, and display addresses is shown in the following table:Urb嘉泰姆

elevenAddress Command Settings (Set Display Address C0H~CFH)Urb嘉泰姆

Example of Display Control Command:

Adjustable pulse width (1/16~14/16), used to adjust brightnessUrb嘉泰姆

Display switch control, supporting energy-saving modeUrb嘉泰姆

6、 Hardware design suggestions

6.1. Power filter:A 100 μ F electrolytic capacitor and a 104 (100nF) ceramic capacitor should be connected in parallel between VDD and VSS, with a layout as close to the chip as possible and a circuit length not exceeding 3cm,Urb嘉泰姆
        To enhance anti-interference ability.Urb嘉泰姆

6.2. Communication line protection:DIN and SCL K lines can be connected in series with 100~200Ω Resist and connect a 100pF capacitor in parallel to ground to suppress high-frequency interference.Urb嘉泰姆

6.3. Selection of driving voltage:If using a blue LED (with a conduction voltage drop of about 3V), it is recommended to use a power supply voltage of 5V to ensure brightness.Urb嘉泰姆

6.4. Anti interference design:In strong interference environments such as induction cookers, it is recommended to reduce communication frequency and strengthen the shielding design between power and ground.Urb嘉泰姆

7、 Application Circuit Example

7.1. Common cathode digital tube driver circuit:SEG output is connected to the LED anode, and GRID output is connected to the cathode, achieving dynamic display through scanning.Urb嘉泰姆
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7.2. Common anode digital tube driver circuit:An external PNP transistor or MOS transistor is required for level conversion, and the GRID output control bit is selected.Urb嘉泰姆
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▲ Attention:1. A capacitor must be connected between VDD and VSS of CXLE88149B. The recommended parameters are 100uF and 104 capacitors, and the PCB board wiring should be done as much as possibleUrb嘉泰姆

Place the quantity close to the CXLE88149B chip, and the length of the circuit composed of VCC, VSS, and capacitors should not exceed 3CM to enhance the filtering effect;Urb嘉泰姆
2. Pulling down two 100pF capacitors connected to the DIO and SCLK communication ports can reduce interference to the communication ports;Urb嘉泰姆
3. If the conduction voltage of the digital tube is reduced by about 3V (blue light), then the CXLE88149B should be powered by 5V;Urb嘉泰姆
4. When the chip operates in strong interference environments such as induction cookers, it is recommended to reduce the communication frequency between CXLE88149B and MCU appropriately, which can facilitate communicationUrb嘉泰姆
String resistors on the mouth, recommended size between 100-200Ω.Urb嘉泰姆

8、 Package size (SOP28/SSOP28)

8.1.SOP28Total length 17.93-18.03mm, width 7.52-7.62mmUrb嘉泰姆

8.2.SSOP28Total length 9.90~10.00mm, width 3.90~4.00mm, suitable for compact designUrb嘉泰姆

9、 Precautions

9.1. Power on initializationAfter the chip is powered on, the contents of the display register are uncertain. It is recommended to write 0x00 to all video memory addresses (C0H~CFH) for clearing to avoid garbled characters.Urb嘉泰姆

9.2. Communication timing sequenceStrictly follow the data establishment time (tSETUP≥ 100ns) and retention time (tHOLD≥ 100ns) operation.Urb嘉泰姆

9.3. Heat dissipation designPay attention to PCB heat dissipation design when driving with high current for a long time to avoid overheating and damage.Urb嘉泰姆

10、 Summary

            CXLE88149B, as a fully functional and simple interface LED driver chip, is very suitable for digital tube driver solutions in industrial control, home appliance display, instrumentation and other fields. Its flexible instruction set, reliable electrical performance, and rich packaging options make it the preferred device for engineers in display driver design.Urb嘉泰姆

If you need the latest data manual or technical support, it is recommended to contact the supplier or official technical support channel to obtain the latest version of the information.Urb嘉泰姆

11、 Selection Guide for Related Chips;                        More similar products ....Urb嘉泰姆

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