CXLE88141N is a driver control chip specially designed for LED display and keyboard scanning. It integrates multiple functional modules and supports multiple display modes (10 segments × 7 bits to 13 segments × 4 bits) and 10 × 2 keyboard matrix scanning. The chip adopts power CMOS technology, with brightness adjustment, serial communication interface and built-in RC oscillator, which is suitable for display Drive requirements of various consumer electronics products.
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[ CXLE88141N ]"
CXLE88141N: a high-performance LED driver and keyboard scanning control chip
CXLE88141N is a special control circuit integrated with LED driver and keyboard scanning function, which is widely used in the display control of VCR, VCD, DVD, home theater and other equipment. This chip adopts SOP28 package, built-in MCU digital interface, data latch, high voltage drive circuit and keyboard scanning module, with high performance, high reliability and flexible application configuration. This paper will deeply analyze the functional characteristics, CXLE88141N, instruction system, data transmission mode and typical application circuit of pin connections, providing comprehensive technical reference for engineers and electronic enthusiasts.
I. Overview of CXLE88141N
CXLE88141N is a driver control chip specially designed for LED display and keyboard scanning. It integrates multiple functional modules and supports multiple display modes (10 segments × 7 bits to 13 segments × 4 bits) and 10 × 2 keyboard matrix scanning. The chip adopts power CMOS technology, with brightness adjustment, serial communication interface and built-in RC oscillator, which is suitable for display Drive requirements of various consumer electronics products.
II. Main features
2.1. Multiple Display modes: Supports 4 to 7 bits and 10 to 13 segments.
2.2. Keyboard scanning: 10 × 2 matrix keyboard scan, support interrupt output (KEYINT)
2.3 brightness adjustment: 8-level duty cycle adjustable, support brightness control
2.4. Communication interface: Serial Interface (CLK, STB, DIO), compatible with multiple MCU
2.5. Built-in oscillator: RC oscillation (450kHz ± 5%)
2.6. Encapsulation form: SOP28
3. Detailed explanation of pin functions
CXLE88141N pins include data input/output (DIO), Chip selection (STB), clock (CLK), key scan input (K1 ~ K2), segment output (SEG1/KS1 ~ SEG10/KS10), bit output (GRID1 ~ GRID4), etc. All input pins have built-in pull-up resistor and support flexible external connection.
▲Note: Our company has integrated 10K pull-up resistor inside the chip. DIO controls the action of N tubes at failling edge of the clock, and reads at this time
The number of times is unstable. You can refer to Figure (6) to stabilize the reading on the rising edge of the clock.
4. Display register and display mode
The chip contains 14 display register units (00H ~ 0DH) and supports automatic address addition or fixed address mode. Users can write display data through the serial interface, and the data is transmitted in order from low to high, supporting co-negative or co-Positive Digital Tube drivers.
This register stores data transmitted from external devices to CXLE88141N through a serial interface. The address ranges from 00H-0DH to a total of 14 bytes.
, corresponding to the LED lights connected to the chip SGE and GRID pins respectively, the distribution is as follows:
When writing LED display data, it operates from low to high in the display address and from low to high in the data byte.
V. Keyboard scanning function
CXLE88141N automatically completes keyboard scanning, and users only need to read key values by time series. Key scan data is stored in a specific register and can read up to 5 bytes. Key combination detection is supported, but hardware design is required to avoid signal conflicts.
The key scan matrix is 10 × 2 bits, as shown in the following figure.:
The key scan data storage address is as follows. After the read key command is sent first, Button bytes of BYTE1-BYTE5 data are read.
Data is output from the low bit, where B6 and B7 bits are invalid bits, and the chip output is 0. Button of chip K and KS pins
When pressed, the BIT in the corresponding byte is 1.
▲Note: 1. CXLE88141N can read up to 5 bytes, and cannot read more.
2. Read data bytes can only be read from BYTE1-BYTE5 in sequence and cannot be read across bytes. For example, K2 and KS10 on hardware
When the corresponding button is pressed, to read this button data, you must read the 4th bit of the 5th byte before reading the data.
; When multiple keys are pressed, for example, K1 and KS10,K2 and KS 500.00G keys are pressed at the same time, the B3 and B4 bits of BYTE5 bytes are 1.
3. The key combination can only be the same KS and different K1 combinations.
VI. Instruction system
The first byte entered by DIO after STB failling edge is used as an instruction. After decoding, it takes up to B7 and B 300.00G bits
Distinguish different instructions.
Invalid (the previously transmitted instruction or data remains valid).
The chip supports four instruction types, which are distinguished by bits B7 and B6:
6.1 Display mode settings: specifies the number of segments and bits.
This command is used to set the number of selected segments and bits (4 to 7 bits, 10 to 13 segments). When the instruction is executed, the display is forcibly closed.
To send the display control command to turn on the display, the data content originally displayed will not be changed, but when the same mode is set, the above situation
Does not happen.
6.2. Data command settings: set data read/write mode, address mode, etc.
This command is used to set data write and read. Bits B1 and B0 cannot be set to 01 or 11.
6.3. Address command settings: sets the start address of the display register.
This command is used to set the address of the display register.
If the address is set to 0EH or higher, the data is ignored until the valid address is set.
When power on, the address is set to 00h by default.
6.4. Display control commands: control the display switch and brightness level
VII. Serial data transmission
Data is read or written on the rising edge of CLK, and STB is used to initialize communication. Pay attention to the waiting time (Twait ≥ 1μs) when reading key values. Supports automatic address addition mode and fixed address mode to meet different programming requirements.
Both the read and receive bits operate on the rising edge of the clock.
7.1. Data receiving (writing data)
7.2. Read data (read data)
▲Note: When reading data, you need to set the command from the 8th rising edge of the serial clock CLK to CLK failling edge to read data.
A wait time Twait (minimum 1 μs).
7.3. Serial data transmission during application:
7.3.1) address increase mode
Using the automatic address plus 1 mode, setting the address is actually the starting address of the transmitted data stream. Start address command
After the word is sent, the "STB" does not need to be raised to follow the data transmission. The maximum value is 14 bytes. After the data transmission is completed, the "STB" is raised.
Command1: Set the display mode
Command2: set data commands
Command3: Set the display address
Data1 ~ n: transmit display data to the Command3 address and the following address (up to 14 bytes)
Command4: Display Control commands
7.3.2) 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.
Bi, "STB" does not need to be raised, followed by the transmission of 1byte data, and the "STB" will be raised only after the data transmission is completed. Then reset
Two data storage addresses, up to 14 bytes of data transfer completed, "STB" is set to high.
Command1: Set the display mode
Command2: set data commands
Command3: set display address 1
Data1: transfer display data from 1 to Command3 addresses
Command4: set display address 2
Data2: transfer display data from 2 to Command4 addresses
Command5: Display Control commands
7.3.2) read button time series
Command1: Set the display mode
Data1 ~ 5: Read button data
7.3.2) program design flow chart:
7.3.2.1)The program design flow chart using automatic address plus one:
7.3.2.1) program design flow chart with fixed address:
8. Display and button Application examples
8.1. Co-Yin digital tube driver:To display the number "0", the ~ f segment must be highlighted when GRID1 is low, and the corresponding data value is 3FH.
Figure 7 shows the connection diagram of co-negative digital tube. If you let the digital tube display "0", you need to set the power to low in GRID1.
When it is flat, set SEG1,SEG2,SEG3,SEG4,SEG5,SEG6 to high level and SEG7 to low level,
View the address table in figure (2). You only need to write data 3FH in the 00h address unit to display "0" on digital tube ".
8.2. Co-Yang digital tube drive
The SEG level must be controlled when multiple grids are low. The specific data must be configured according to the hardware connection.
Figure 8 shows the connection diagram of co-Yang digital tube. If you let the digital tube display "0", then you need to go to GRID1 and GRID2.
, when GRID3,GRID4,GRID5,GRID6 is low, the SEG1 is high, and when GRID7 is low
Set SEG1 to low. Write 01H of data to address units 00H,02H,04H,06H,08H,0AH respectively, and the rest
Write data for all address units of 00H.
▲Note: SEG1-11 is the open drain output of p tube and GRID1-7 is the open drain output of N tube. When using, SEG1-11 can only be connected to the LED Yang
Pole, GRID can only be connected to the cathode of LED, and cannot be connected in reverse.
8.3. Button detection
The KEYINT pin outputs a low level when a key is pressed. You can read the key value register to determine the status of Button.
Key scanning is automatically completed by CXLE88141N and is not controlled by users. Users only need to read key values according to the time series. To complete a key scan
Two display cycles are required, and a display cycle requires T = 8 x500US. Two different button are pressed in 8ms and read twice.
The key value of is the button key value pressed first.
Observe the output key scan waveform of SEG1/KS1 and SEG2/KS2 with oscilloscope according to figure (9), as shown in figure (10).
IC SEGN/KSN waveform during keyboard scanning:
Tdisp is related to the oscillation frequency of IC operation. Our company has improved CXLE88141N many times, and the oscillation frequency is not completely the same. 500US
For reference only, the actual measurement shall prevail.
Generally, figure (11) can meet the design requirements of Button.
When S1 is pressed, "1" is read in B0 of the first byte ". If multiple button are pressed, multiple "1" will be read"
, when S2 and S3 are pressed, you can read "1" in B1 and B3 of the first byte ".
▲Note: precautions for using compound keys:
SEG1/KS1-SEG10/KS10 is reused for display and button scan. Take figure (12) as an example, the display needs D1 to be on, D2 to be off,
You need to set SEG1 to "1" and SEG2 to "0". If S1 and S2 are pressed at the same time, it is equivalent to SEG1 and SEG2 is short-circuited. This
When D1,D2 are all lit.
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 resistance on SEG1-SEG N is shown in figure (14). The resistance value of the resistance should be 510 Ohm, which is too much
Button of the failures may not solve the problem of display interference if it is too small.
3. Or series diode is shown in figure (15).
CXLE88141N button interrupt signal
The new pin KEYINT, which is usually high, outputs a low level when button is pressed.
IX. Hardware design attention
9.1 SEG pin is p tube open drain output, should be connected to LED anode;
9.2.GRID pin is N tube open drain output, which should be connected to LED cathode;
9.3. Avoid direct short circuit between SEG and GRID, and prevent display interference by series resistor or diode.
X. Electrical parameters
10.1 working voltage: 3V to 5.5V
10.2. Driving current: SEG output reaches 25mA(Vo = VDD-2V),GRID output reaches 140mA(Vo = 0.3V)
10.3. Oscillation frequency: Typical value: 500kHz
10.4. Operating temperature:-40 ℃ ~ 85 ℃
10.5. Limit parameters (Ta = 25℃, Vss = 0V)
10.6 normal operating range (Vss = 0V)
10.7. Electrical characteristics (VDD = 4.5~5.5V, Vss = 0V)
10.8. Switching characteristics (VDD = 4.5~5.5V)
10.9. Time series characteristics (VDD = 4.5~5.5V)
10.10. Time Series Waveform diagram:
11. Typical application circuit
CXLE88141N can drive co-yin or co-Yang digital tube, and the external MCU communicates through DIO, CLK, and STB. Pay attention to the configuration of filter capacitor and pull-up resistor in the application circuit to ensure signal stability.
11.1.CXLE88141N drive common female digital screen wiring circuit diagram (18):
11.2.CXLE88141N drive co-Yang digital screen wiring circuit diagram (19):
▲Note: 1. Filter capacitor wiring between VDD and GND should be placed as close to PCB board chip as possible to enhance the filtering effect.
2. Three 101p capacitors connected to the DIO, CLK, 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 CXLE88141N power supply.
12. Summary
CXLE88141N is a functional and flexible LED driver and keyboard scanning control chip, which is suitable for the display interface design of various consumer electronics products. Its serial interface, multiple display modes, keyboard interrupt output and other characteristics make it an ideal choice for engineers in designing and optimizing human-computer interaction interfaces.
Thirteen, relevant chip selection guideMore 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 |
