CXLE88143N is a special integrated circuit for LED driver control integrated with keyboard scanning interface. It is manufactured by CMOS technology and has multiple functions such as MCU digital interface, data latch, LED driver and keyboard scanning. With its high reliability, excellent stability and strong anti-interference capability, the chip is widely used in intelligent water heaters, microwave ovens, washing machines, air conditioners, induction cookers and other household appliances, as well as set-top boxes, electronic scales, smart meter and other digital tube or LED display devices.
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[ CXLE88143N ]"
CXLE88143N: analysis of high-performance LED driver and keyboard scanning control chip
I. Overview
CXLE88143N is a special integrated circuit for LED driver control integrated with keyboard scanning interface. It is manufactured by CMOS technology and has multiple functions such as MCU digital interface, data latch, LED driver and keyboard scanning. With its high reliability, excellent stability and strong anti-interference capability, the chip is widely used in intelligent water heaters, microwave ovens, washing machines, air conditioners, induction cookers and other household appliances, as well as set-top boxes, electronic scales, smart meter and other digital tube or LED display devices.
II. Main features
1. Display capability: supports 16-segment × 8-bit LED display
2. Keyboard matrix: supports up to 8 × 4 matrix button
3. Brightness adjustment: 8-level duty cycle adjustable, support brightness control
4. Communication interface: Serial Interface (CLK, STB, DIN, DOUT), supports data read/write and button scan
5. Built-in functions: RC oscillator, power-on reset circuit, data latch
6. Anti-interference design: optimize the circuit to prevent dark and bright problems caused by LED reverse bias and leakage
7. Encapsulation form: LQFP44 package, suitable for high-density PCB layout
3. Detailed explanation of pin functions
There are 44 pins in CXLE88143N, including the following categories:
| Pin Name | Function description | Remarks |
|---|---|---|
| DOUT | Serial data output | Can be used with DIN shorting as DIO |
| DIN | Serial data input | Can be used with DOUT shorting as DIO |
| SCLK | Serial clock input | Rising edge reading and writing data |
| STB | Chip selection signal | Failling edge initialize communication |
| K0 ~ K3 | Key scan data input | Supports 4 × 8 matrix button |
| SEG1 ~ SEG16 | Segment output (LED anode Drive) | P tube open drain output |
| GRID1 ~ GRID8 | Bit output (LED cathode Drive) | N tube open drain output |
| VDD/VSS | Power/ground | Multi-pin distribution enhances stability |
| NC | Empty feet | Not connected internally |
IV. Instruction system and communication protocol
The first byte entered by DIN after STB failling edge is used as the instruction. After decoding, the highest bits of B7 and B are taken to distinguish different instructions.
CXLE88143N receive commands through the serial interface in the following format:
4.1. Data command settings (B7 = 0, B6 = 1)
4.1.1) write display data: B1B0 = 00
4.1.2) read key scan data: B1B0 = 10
4.1.3) address mode: B0 = 0 (auto-increment), B0 = 1 (fixed address)
4.1.4) mode setting: B0 = 0 (normal mode)
Commands are used to set data write and read. Bits B1 and B0 cannot be set to 01 or 11.
4.2. Display control commands (B7 = 1, B6 = 0)
4.2.1) brightness adjustment: B2 ~ B0 control 8-level duty cycle (1/16~14/16)
4.2.2) Display switch: B3 = 0 (off), B3 = 1 (on)
This command is used to set the Display switch and display brightness adjustment. A total of 8 levels of brightness are available for adjustment.
4.3. Address command (B7 = 1, B6 = 1)
Set the display register address (00H ~ 0FH), a total of 16 bytes, corresponding to 8 bits × 16 segments of display data.
This command is used to set the address of the display register. The maximum valid address is 16 bits (00H-0FH). If the address is set to 10h or higher, data
Ignored until the valid address is set. When power on, the address is set to 00h by default.
V. Display driver and button scan
5.1. Display driver
5.1.1) co-negative digital tube: SEG is connected to the anode, GRID is connected to the cathode, and the corresponding segment selection data can be written to display.
Figure 7 shows the connection diagram of the common cathode digital tube. If the digital tube is displayed as "0", only the 00h (GRID1) address needs to be removed from the low position.
Start writing 0x3F data. At this time, the data corresponding to each SEG1-SEG8 is as follows.
5.1.2) Gongyang digital tube: You must write segment selection data to the corresponding GRID address and write 00h to the rest address.
Figure 8 shows the connection diagram of the common anode digital tube. If the digital tube is displayed as "0", the address units 00H(GRID1), 02H(GRID2),
04H(GRID3), 06H(GRID4), 08H(GRID5), 0AH(GRID6) write data for 01h, the rest of the addresses 0CH(GRID7), 0EH(GRID8)
The unit writes all data for 00 hours. The data corresponding to each SEG1-SEG8 is shown in the following table.
▲Note: whether driving the common cathode digital tube or driving the common anode digital tube, SEG pin can only be connected to the LED anode, GRID can only be connected to the LED cathode, no
It can be connected in reverse.
5.2. Button scan
5.2.1) support 8 × 4 matrix button, automatic scanning, cycle is about 4.7ms.
Button scanning is automatically completed by CXLE88143N and is not controlled by users. Users only need to read key values according to the time series. Complete a key scan
One display cycle is required, and a display cycle is about T = 4.7ms. Two different button are pressed within 4.7ms. The key values read twice are all
The key value of the button pressed first.
CXLE88143N after power-on, the internal scanning waveform of SEG1/KS1-SEG8/KS8 is shown in figure (10):
▲Note: a cycle time is related to the oscillation frequency of the IC, and the oscillation frequency of each IC is not completely consistent. The above data is for reference only
The actual measurement shall prevail.
5.2.2) key-value data is output in the order of BYTE1 to BYTE4, and each byte contains four key states.
Button reuse:The problem of composite button is abnormal: SEG1/KS1-SEG8/KS8 is reused by display and button scan. Take figure (12) as an example,
The display needs D1 to be on and D2 to be off. You need to set SEG1 to "0" and SEG2 to "1". If S1 and S2 are pressed at the same time, it is equivalent to SEG1 and SEG2 is short-circuited,
At this time, D1 and D2 are all lit up.
Solution:
1. On the hardware, you can set the keys that need to be pressed at the same time on different k lines as shown in figure (13),
2. The series diode is shown in figure (14).
▲Note: We recommend that you use the same K key with different KS as the composite button.
5.3. Display register address:
This register stores data transmitted from external devices to CXLE88143N through the serial interface. The maximum valid address is 16 bytes from 00H-0FH,
Corresponding to the SEG and GRID pins of the chip respectively, the specific allocation is shown in figure (2):
When writing LED display data, it operates from low to high in the display address and from low to high in the data byte.
▲Note: the value stored in the chip display register at the moment of power-on may be randomly uncertain. At this time, the customer directly sends the Open Screen command,
Garbled codes may appear. Therefore, we recommend that the customer power on the display register for clear operation, that is, the 16-bit memory address after power-on.
0x 00 is written to all data in (00H-0FH).
5.4. Serial data transmission format:
Read and receive 1 BIT are operating on the rising edge of the clock
▲Note: 1. When reading data, you need to set the command from the 8th rising edge of the serial clock CLK to the CLK failling edge read data.
Wait time Twait (minimum 2 μs). For more information, see Time series feature table.
2. The above time series are DOUT and DIN shorted together as DIO usage.
5.5. Serial data transmission during application:
5.5.1) address increase mode
Using the automatic address plus 1 mode, setting the address is actually the starting address of the transmitted data stream. The start address command word has been sent,
STB does not need to be high to transmit data immediately. It can be up to 16 bytes at most.
Command1: set data commands
Command2: Set the display address
Data1 ~ n: transmit display data to the Command2 address and the following address (up to 16bytes)
Command3: Display Control commands
5.5.2) fixed address mode
Using the fixed address mode, setting the address is actually setting the address where the 1byte data to be transmitted is stored. The address has been sent, "STB"
You do not need to set the value to high. The data is transmitted immediately after 1byte. The STB value is set to high only after the data is transmitted. Then reset the address where the second data needs to be stored,
Up to 16 bytes of data has been transferred, and the STB is set to high.
Command1: set data commands
Command2: set display address 1
Data1: transfer display data from 1 to Command2 addresses
Command3: set display address 2
Data2: transfer display data from 2 to Command3 addresses
Command4: Display Control commands
5.5.3) read button time series
Command1: Set the read button command
Data1 ~ 4: reads button data
▲Note: the above time series are DOUT and DIN shorted together as DIO usage.
5.5.4) program design flow chart using automatic address plus one and fixed address:
5.5.4.1) program design flow chart using automatic address plus one:
5.5.4.2) program design flow chart with fixed address:
VI. Application circuit design suggestions
6.1. Power filtering: add 100 LEDs F and 104 capacitors between VDD and GND, and place them close to the chip.
6.2. Communication anti-interference: DIO, SCLK, and STB lines are connected in series with 100pF capacitors.
6.3.LED type adaptation: blue LED is recommended to use 5V power supply.
6.4. Composite button processing: it is recommended to design composite keys on different k lines or series diodes to prevent short circuit.
6.5. Hardware circuit diagram of CXLE88143N driver co-Yin digital screen
6.6.CXLE88143N drive co-Yang digital screen wiring circuit diagram (19)
▲Note:1. The filter capacitor between VDD and GND should be placed as close as possible to CXLE88143N chips in PCB wiring to enhance the filtering effect.
2. Three 101(100pF) capacitors connected to the DIO(DIN, DOUT), SCLK, and STB communication ports can reduce the interference to the communication ports.
3. Since the conduction voltage of blue light digital tube is reduced by about 3V, 5V should be selected for CXLE88143N power supply.
4. It is recommended to use DIN and DOUT ports together as DIO in the actual circuit.
VII. Summary of electrical parameters
7.1. Working voltage: 5V
7.2. Driving current: SEG output 20-50ma, GRID output 80-140ma
7.3. Communication clock: up to 1MHz
7.4. Working temperature:-40 ℃ ~ 85 ℃
7.5. Limit parameters (Ta = 25℃, Vss = 0V)
7.6. Normal operating range (Vss = 0V)
7.7. Electrical characteristics (VDD = 5V, Vss = 0V)
7.8. Switching characteristics (VDD = 5V)
7.9. Time series characteristics (VDD = 5V)
7.10. Time Series Waveform diagram:
VIII. Summary
CXLE88143N is a fully functional and stable LED driver and keyboard scanning control chip, suitable for a variety of household appliances and industrial display scenarios. Its flexible instruction system, powerful driving ability and good anti-interference design make it an ideal choice for high reliability display control.
IX,Relevant chip selection guide More similar products.....
| Model | Number of interfaces | Drive dot matrix number | Segment/bit | Co-negative Drive | Co-positive drive | Button | Encapsulation form | Remarks |
| CXLE88134N | 3 | 28 | 7*4 | 7-segment 4-bit | - | - | SOP16/DIP16 | LED panel display driver chip |
| CXLE88135N | 3 | 21 | 8*2/7*3 | 8-segment 2-bit/7-segment 3-bit | - | 6*1 | SOP16 | LED panel display driver chip |
| CXLE88136N | 3 | 35 | 5*7/8*4 | 7-segment 5-bit/8-segment 4-bit | 7 segments and 5 digits | 5*1 | SOP18/DIP18 | LED panel display driver chip |
| CXLE88137BN | 3 | 48 | 6*7/9*4 | 7-segment 6-bit/9-segment 4-bit | 7-segment 6-bit | 6*1 | SOP20 | LED panel display driver chip |
| CXLE88137N | 3 | 48 | 8*6/10*4 | 8-segment 6-bit/10-segment 4-bit | - | - | SOP20 | LED panel display driver chip |
| CXLE88138C | 4 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88138N | 4 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88139N | 3 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | - | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88141N | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88142A | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88142E | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88143AN | 3 | 128 | 16*8 | 16-segment 8-bit | 8-segment 16-bit | - | SOP32 | LED panel display driver chip |
| CXLE88143BN | 3 | 112 | 14*8 | 14-segment 8-bit | 8-segment 14-bit | 8*2 | SOP32 | LED panel display driver chip |
| CXLE88143CN | 3 | 120 | 15*8 | 15-segment 8-bit | 8-segment 15-bit | 8*1 | SOP32 | LED panel display driver chip |
| CXLE88143DN | 3 | 96 | 12*8 | 12-segment 8-bit | 8-segment 12-bit | 8*4 | SOP32 | LED panel display driver chip |
| CXLE88143N | 4 | 128 | 16*8 | 16-segment 8-bit | 8-segment 16-bit | 8*4 | QFP44 | LED panel display driver chip |
| CXLE88147N | 3 | 80 | 10*8 | 10-segment 8-bit | 8-segment 10-bit | 8*3 | SOP28 | LED panel display driver chip |
| CXLE88148N | 3 | 64 | 8*8 | 8-segment 8-bit | 8 segments and 6 digits | 4*2 | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88149B | 2 | 128 | 8*16 | 8-segment 16-bit | 16-segment 8-bit | - | SOP28, SSOP28 | LED panel display driver chip |
| CXLE88155N | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP24/SSOP24/SDIP24 | LED panel display driver chip |
| CXLE88171 | 4 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88172 | 2 | 128 | 8*16 | 8-segment 16-bit | 16-segment 8-bit | - | SOP24 | LED panel display driver chip |
| CXLE88173 | 2 | 144 | 8*9*2 | Positive and negative push digital tube | Positive and negative push digital tube | - | QSOP24 | LED panel display driver chip |
| CXLE88174 | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | Touch Button 8 | SOP32 | LED panel display driver chip |
| CXLE88175 | 5 | 120 | 15*8 | 15-segment 8-bit | 8-segment 15-bit | 8*1/8 | QFN48 | LED panel display driver chip |
| CXLE88176 | 3 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | 10*1 | SOP24 | LED panel display driver chip |
| CXLE88156 | 3 | 128 | 8*16 | 8-segment 16-bit | 16-segment 8-bit | - | SOP32 | LED panel display driver chip |
| CXLE88134 | 3 | 28 | 7*4 | 7-segment 4-bit | - | - | SOP16/DIP16 | LED panel display driver chip |
| CXLE88135 | 3 | 21 | 8*2/7*3 | 8-segment 2-bit/7-segment 3-bit | - | 6*1 | SOP16 | LED panel display driver chip |
| CXLE88136 | 3 | 35 | 5*7/8*4 | 7-segment 5-bit/8-segment 4-bit | 7 segments and 5 digits | 5*1 | SOP18/DIP18 | LED panel display driver chip |
| CXLE88137 | 3 | 48 | 8*6/10*4 | 8-segment 6-bit/10-segment 4-bit | - | - | SOP20 | LED panel display driver chip |
| CXLE88137A | 3 | 48 | 6*7/9*4 | 7-segment 6-bit/9-segment 4-bit | 7-segment 6-bit | 6*1 | SOP20 | LED panel display driver chip |
| CXLE88138 | 4 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88139 | 3 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | - | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88140A | 4 | 77 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*1 | SOP32 | LED panel display driver chip |
| CXLE88140B | 3 | 77 | 11*7/14*4 | 11 Segment 7 bit/14 Segment 4 bit | 7-segment 11-bit | 10*3 | QFP44 | LED panel display driver chip |
| CXLE88141 | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88142 | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88143 | 4 | 128 | 16*8 | 16-segment 8-bit | 8-segment 16-bit | 8*4 | QFP44 | LED panel display driver chip |
| CXLE88143A | 3 | 128 | 16*8 | 16-segment 8-bit | 8-segment 16-bit | - | SOP32 | LED panel display driver chip |
| CXLE88143B | 3 | 112 | 14*8 | 14-segment 8-bit | 8-segment 14-bit | 8*2 | SOP32 | LED panel display driver chip |
| CXLE88143C | 3 | 120 | 15*8 | 15-segment 8-bit | 8-segment 15-bit | 8*1 | SOP32 | LED panel display driver chip |
| CXLE88143D | 3 | 96 | 12*8 | 12-segment 8-bit | 8-segment 12-bit | 8*4 | SOP32 | LED panel display driver chip |
| CXLE88144 | 3 | 35 | 7*5/8*4 | 7-segment 5-bit/8-segment 4-bit | - | 7*1 | DIP18 | LED panel display driver chip |
| CXLE88145 | 2 | 32 | 8*4 | - | 8-segment 4-bit | 8*2 | DIP18 | LED panel display driver chip |
| CXLE88146 | 2 | 48 | 8*6 | - | 8 segments and 6 digits | 8*2 | SOP20/DIP20 | LED panel display driver chip |
| CXLE88147 | 3 | 80 | 10*8 | 10-segment 8-bit | 8-segment 10-bit | 8*3 | SOP28 | LED panel display driver chip |
| CXLE88148 | 3 | 64 | 8*8 | 8-segment 8-bit | 8 segments and 6 digits | 4*2 | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88149 | 2 | 128 | 8*16 | 8-segment 16-bit | 16-segment 8-bit | - | SOP28/SSOP28 | LED panel display driver chip |
| CXLE88150 | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88151 | 2 | 32 | 8*4 | 8-segment 4-bit/7-segment 4-bit | - | 7*4 | SOP16/DIP16 | LED panel display driver chip |
| CXLE88152 | 2 | 28 | 7*4 | - | 7-segment 4-bit | 7*1 | SOP16/DIP16 | LED panel display driver chip |
| CXLE88153 | 1 | 40 | 7*6/8*5 | 7-segment 6-bit/8-Segment 5-bit | 6-segment 7-bit/5-segment 8-bit | - | SOP16 | LED panel display driver chip |
| CXLE88154 | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88155 | 3 | 70 | 10*7/13*4 | 10-segment 7-bit/13-segment 4-bit | 7-segment 10-bit | 10*2 | SOP24/SSOP24/SDIP24 | LED panel display driver chip |
| CXLE88133 | 2 | 256 | 32*8/24*16 | 32-segment 8-bit/24-segment 16-bit | 8-segment 32-bit/16-segment 24-bit | - | LQFP48/LQFP52 | LED panel display driver chip |
| CXLE88132 | 4 | 256 | 32*8/24*16 | 32-segment 8-bit/24-segment 16-bit | 8-segment 32-bit/16-segment 24-bit | - | LQFP48/LQFP52 | LED panel display driver chip |
