CXLE88137BN is a highly integrated control chip designed for LED display driver and keyboard scanning. The chip is manufactured by advanced power CMOS technology, with integrated MCU digital interface, data latch, LED high voltage driver and keyboard scanning circuit. It is widely used in digital tube display driver of VCR, VCD, DVD and home theater equipment. Its package form is SOP20, which has good heat dissipation and welding reliability.
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[ CXLE88137BN ]"
CXLE88137BN is a highly integrated control chip designed for LED display driver and keyboard scanning. The chip is manufactured by advanced power CMOS technology, with integrated MCU digital interface, data latch, LED high voltage driver and keyboard scanning circuit. It is widely used in digital tube display driver of VCR, VCD, DVD and home theater equipment. Its package form is SOP20, which has good heat dissipation and welding reliability.
First, the main characteristics
1.1. Display flexibility: Support multiple display modes (6 segments × 7 bits to 9 segments × 4 bits) to adapt to different display requirements.
1.2. Keyboard function: Integrated 6 × 1Bit keyboard scanning interface, support multi-key simultaneous detection.
1.3. brightness adjustment: 8-level duty cycle is adjustable to realize LED brightness control.
1.4. Communication Interface: Communicate with the master MC through CLK, STB, DIO three-wire serial interface.
1.5. Built-in oscillator: Built-in RC oscillator circuit (typically 450kHz), saving external components.
1.6. Power Management: Built-in power-on reset circuit, support 5V ± 10% logic power supply.
Second, pin definition and function
The CXLE88137BN 20 pins include power, ground, serial communication lines, and multiple segment/bit output pins, some of which are multiplexed as keyboard scan inputs. In particular, it should be noted that the DIO port should be externally connected with a 10kΩ pull-up resistor when reading the key to ensure the stability of data reading.
▲ Note: When DIO port outputs data, it is N-tube open-drain output. When reading the key, it is necessary to externally connect 1K-10K pull-up resistor. The Company Pushes
Recommended 10K pull-up resistor. DIO controls the action of the N tube at the falling edge of the clock. At this time, the reading is unstable. You can refer to Figure (6),
The reading is stable on the rising edge of the clock.
Third, display and keyboard scanning mechanism
The chip contains a 14-byte display register, which is used to store the display data of each segment and bit of the LED. Users can write data through the serial port, support automatic address increase and fixed address two modes.
The keyboard scan uses a 6 × 1 matrix structure, which can read up to 3 bytes of key value data and supports multi-key simultaneous press recognition. Read keys in order, not across bytes.
3.1. Display:
3.1.1) Drive the common negative digital tube:
Fig. 7 shows the connection diagram of the common negative digital tube. if the digital tube displays "0", then you need to set GRID1 to low level
Let SEG1,SEG2,SEG3,SEG4,SEG5,SEG6 be high and SEG12 be low,
Looking at the address table shown in figure (2), you only need to write data 3FH in the 00H address unit and 00H in the 01H address unit to make
3.1.2) Drive Gongyang Digital Tube:
Fig. 8 shows the connection diagram of the common yang digital tube. if the digital tube displays "0", you need to display "0" in GRID1,GRID2,
Let SEG1 be high when GRID3,GRID4,GRID5,GRID6 are low, and let SEG1 be low when GRID7 is low
is a low level. To write data 01H to address units 00h, 02h, 04h, 06h, 08h, 0ah respectively, the rest of the address list
Yuan all write data 00H.
▲ Note: The SEG1-11 is P-tube open-drain output and the GRID1-7 is N-tube open-drain output. When in use, the SEG1-11 can only be connected to the anode of the LED.
Polar, GRID can only be connected to the cathode of the LED, not reverse.
3.2. Keyboard Scan:
You can observe the output waveforms of SEG1/KS1 and SEG2/KS2 with an oscilloscope according to figure (9), and the output waves of SEGN/KSN
Figure (10).
Tdisp is related to the oscillation frequency of IC work. Our CXLE88137BN has been improved many times, and the oscillation frequency is not completely consistent. 500US
For reference only, the actual measurement shall prevail.
In general, figure (11) can be used to meet the requirements of key design.
When S1 is pressed, "1" is read in B0 of the first byte ". If multiple keys are pressed, multiple "ones" will be read ",
When S2 and S3 are pressed, "1" can be read in B1 and B3 of the first byte ".
Four, the instruction system
The first byte entered by the DIO after the falling edge of the STB serves as an instruction. After decoding, the highest B7 and B 300.00g bits are taken
Distinguish between different instructions.
If the STB is set to high level during command or data transmission, serial communication is initialized and the command or data being transmitted
Invalid (previously transferred instructions or data remain valid).
The chip supports four instruction types, which are distinguished by the upper two bits (B7 and B6) of the first byte of the serial port:
4.1. Display Mode Settings: Configure the number of display segments and bits.
This instruction is used to set the number of selected segments and bits (4 to 7 bits, 6 to 9 segments). When the command is executed, the display is forcibly closed.
To send the display control command to turn on the display, the original displayed data content will not be changed, but when the same mode is set, the above situation
It doesn't happen.
4.2. Data Command Settings: Select data read and write mode, address mode, etc. This instruction is used to set data write and read. Bits B1 and B0 do not allow 01 or 11 to be set.
4.3. Address Command SettingsSpecifies the starting address of the display register.
This instruction is used to set the address of the display register.
If the address is set to 0EH or higher, the data is ignored until a valid address is set.
At power-on, the address is set to 00H by default.
4.4. Display control commands.: Control the display switch and brightness level (1/16 to 14/16 duty cycle).
Five, typical application circuit
The CXLE88137BN can drive the common yin or common yang digital tube. When driving the common negative digital tube, SEG should be set to high level when the corresponding GRID is low level; When driving the common positive digital tube, reverse control is required. In the application circuit, it is recommended to place filter capacitors nearby between VDD and GND, and add 100pF capacitors on DIO, CLK and STB lines to suppress interference.
5.1.CXLE88137BN typical application circuits (16) for driving common-negative digital screens:
5.2.CXLE88137BN typical application circuits (17) used to drive the Gongyang digital screen:
▲ Note: 1. The filter capacitor between VDD and GND should be placed as close to the CXLE88137BN chip as possible on the PCB board to enhance the filtering effect.
2. Three 100P capacitors connected to DIO, CLK and STB communication ports can reduce interference to the communication ports.
3. Since the conduction voltage of the blue digital tube is about 3V, the CXLE88137BN power supply should be 5V.
Six, electrical characteristics and timing
6.1. Normal operating range (Vss = 0V) Operating voltage：5V ± 10%
6.2. Driving ability: SEG output current up to 50mA,GRID absorption current up to 140mA
6.3. Communication timing waveform diagram:: The clock frequency is up to 1MHz, the data setup and hold time are both 100ns, and the key needs to be sampled on the rising edge of the clock when reading.
6.4. Limit parameters (Ta = 25 ℃, Vss = 0V)
6.5. Electrical characteristics (VDD = 4.5~5.5V, Vss = 0V)
6.6. Switching characteristics (VDD = 4.5~5.5V)
6.7. Timing characteristics (VDD = 4.5~5.5V)
Seven, display register address and display mode:
7.1. This register stores the data transmitted from the external device to the CXLE88137BN through the serial interface, and the address is a 14-byte single from 00H-0DH.
The elements correspond to the LED lights connected to the chip SGE and GRID pins, respectively, and are assigned as follows:
7.2. Key scan and key scan data registers:
The key sweep matrix is 6 × 1bit, as follows:
The storage address of the key scan data is as follows. After the key read command is issued first, the BYTE1-BYTE3 bytes of the key data are read and the data is read.
The output starts from the low bit, where B0,B2,B3,B5,B6 and B7 bits are invalid bits, and the chip output is 0 at this time. Chip K and KS pins
When the corresponding key is pressed, the BIT bit in the corresponding byte is 1.
▲ Note: 1. The CXLE88137BN can read up to 3 bytes, and multiple reads are not allowed.
2. Read data bytes can only be read from the BYTE1-BYTE3 in sequence, and cannot be read across bytes. For example: K2 and KS6 on hardware
When the corresponding key is pressed, if you want to read the data of this key at this time, you must read the 4BIT bit of the third byte before you can read the data.
7.3. Serial data transmission format:Both reading and receiving 1 BIT operate on the rising edge of the clock.
Eight, the application of serial data transmission:
8.1.) Address increase mode
Using the address automatic plus 1 mode, setting the address is actually setting the starting address for storing the transmitted data stream. Start Address Command
After the word is sent, "STB" does not need to be set high followed by data transmission, up to 14BYTE, and "STB" is set high only after the data transmission is completed.
Command1: setting display modes
Command2: Set Data command
Command3: setting display address
Data1 ~ n: Transmit display data to the Command3 address and the following address (up to 14 bytes)
Command4: Display Control Commands
8.2) 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. Address sent out
After that, "STB" does not need to be set high, followed by 1BYTE data transmission, and "STB" is set high only after data transmission is completed. Then reset the No.
The address where 2 data need to be stored, up to 14BYTE data transmission is completed, and "STB" is set high.
Command1: setting display modes
Command2: Set Data command
Command3: Set display address 1
Data1: Transmit display data 1 to Command3 address
Command4: Set display address 2
Data2: Transmit display data 2 to Command4 address
Command5: Display Control Commands
8.3) Read key timing
Command1: setting display modes
Data1 ~ 3: read key data
8.4.) Program design flow chart:
8.4.1) Program design flow chart using address automatic plus 1:
8.4.2) Program design flowchart with fixed address:
Nine, summary
CXLE88137BN is a full-featured and stable LED driver and keyboard control chip, especially suitable for display panel control in consumer electronics. Its highly integrated design reduces the number of external components and system costs, while providing flexible display and key handling capabilities. Whether for home theater equipment or industrial control panels, CXLE88137BN provide a reliable solution.
Ten, the relevant chip selection guideMore similar products.....
| Model | Number of Interfaces | Number of driving lattice | Segment/Bit | Common Yin Drive | Gongyang drive | Key | Encapsulation form | Remarks |
| CXLE88134N | 3 | 28 | 7*4 | Section 7, 4 digits | - | - | SOP16/DIP16 | LED panel display driver chip |
| CXLE88135N | 3 | 21 | 8*2/7*3 | 8 segments 2 bits/7 segments 3 bits | - | 6*1 | SOP16 | LED panel display driver chip |
| CXLE88136N | 3 | 35 | 5*7/8*4 | 7-segment 5-bit/8-segment 4-bit | Segment 7, position 5 | 5*1 | SOP18/DIP18 | LED panel display driver chip |
| CXLE88137BN | 3 | 48 | 6*7/9*4 | 7 segments 6 bits/9 segments 4 bits | Segment 7, 6 digits | 6*1 | SOP20 | LED panel display driver chip |
| CXLE88137N | 3 | 48 | 8*6/10*4 | 8 segments 6 bits/10 segments 4 bits | - | - | SOP20 | LED panel display driver chip |
| CXLE88138C | 4 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88138N | 4 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88139N | 3 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | - | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88141N | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88142A | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88142E | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88143AN | 3 | 128 | 16*8 | 16 Segment 8 Bits | 8 Segments 16 Bits | - | SOP32 | LED panel display driver chip |
| CXLE88143BN | 3 | 112 | 14*8 | Segment 14, 8 bits | 8 Segment 14 Bits | 8*2 | SOP32 | LED panel display driver chip |
| CXLE88143CN | 3 | 120 | 15*8 | Segment 15, 8 bits | Segment 8, bit 15 | 8*1 | SOP32 | LED panel display driver chip |
| CXLE88143DN | 3 | 96 | 12*8 | 12 Segment 8 Bits | Segment 8, 12 bits | 8*4 | SOP32 | LED panel display driver chip |
| CXLE88143N | 4 | 128 | 16*8 | 16 Segment 8 Bits | 8 Segments 16 Bits | 8*4 | QFP44 | LED panel display driver chip |
| CXLE88147N | 3 | 80 | 10*8 | Segment 10, 8 bits | 8 Segment 10 Bits | 8*3 | SOP28 | LED panel display driver chip |
| CXLE88148N | 3 | 64 | 8*8 | 8 Segment 8 Bits | Section 8, 6 digits | 4*2 | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88149B | 2 | 128 | 8*16 | 8 Segments 16 Bits | 16 Segment 8 Bits | - | SOP28、SSOP28 | LED panel display driver chip |
| CXLE88155N | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*2 | SOP24/SSOP24/SDIP24 | LED panel display driver chip |
| CXLE88171 | 4 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88172 | 2 | 128 | 8*16 | 8 Segments 16 Bits | 16 Segment 8 Bits | - | SOP24 | LED panel display driver chip |
| CXLE88173 | 2 | 144 | 8*9*2 | forward and reverse push digital tube | forward and reverse push digital tube | - | QSOP24 | LED panel display driver chip |
| CXLE88174 | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | Touch keys 8 | SOP32 | LED panel display driver chip |
| CXLE88175 | 5 | 120 | 15*8 | Segment 15, 8 bits | Segment 8, bit 15 | 8*1/8 | QFN48 | LED panel display driver chip |
| CXLE88176 | 3 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | 10*1 | SOP24 | LED panel display driver chip |
| CXLE88156 | 3 | 128 | 8*16 | 8 Segments 16 Bits | 16 Segment 8 Bits | - | SOP32 | LED panel display driver chip |
| CXLE88134 | 3 | 28 | 7*4 | Section 7, 4 digits | - | - | SOP16/DIP16 | LED panel display driver chip |
| CXLE88135 | 3 | 21 | 8*2/7*3 | 8 segments 2 bits/7 segments 3 bits | - | 6*1 | SOP16 | LED panel display driver chip |
| CXLE88136 | 3 | 35 | 5*7/8*4 | 7-segment 5-bit/8-segment 4-bit | Segment 7, position 5 | 5*1 | SOP18/DIP18 | LED panel display driver chip |
| CXLE88137 | 3 | 48 | 8*6/10*4 | 8 segments 6 bits/10 segments 4 bits | - | - | SOP20 | LED panel display driver chip |
| CXLE88137A | 3 | 48 | 6*7/9*4 | 7 segments 6 bits/9 segments 4 bits | Segment 7, 6 digits | 6*1 | SOP20 | LED panel display driver chip |
| CXLE88138 | 4 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | 10*3 | SOP32 | LED panel display driver chip |
| CXLE88139 | 3 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | - | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88140A | 4 | 77 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*1 | SOP32 | LED panel display driver chip |
| CXLE88140B | 3 | 77 | 11*7/14*4 | 11 segment 7 bits/14 segment 4 bits | Section 7, position 11 | 10*3 | QFP44 | LED panel display driver chip |
| CXLE88141 | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88142 | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88143 | 4 | 128 | 16*8 | 16 Segment 8 Bits | 8 Segments 16 Bits | 8*4 | QFP44 | LED panel display driver chip |
| CXLE88143A | 3 | 128 | 16*8 | 16 Segment 8 Bits | 8 Segments 16 Bits | - | SOP32 | LED panel display driver chip |
| CXLE88143B | 3 | 112 | 14*8 | Segment 14, 8 bits | 8 Segment 14 Bits | 8*2 | SOP32 | LED panel display driver chip |
| CXLE88143C | 3 | 120 | 15*8 | Segment 15, 8 bits | Segment 8, bit 15 | 8*1 | SOP32 | LED panel display driver chip |
| CXLE88143D | 3 | 96 | 12*8 | 12 Segment 8 Bits | Segment 8, 12 bits | 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 | - | Segment 8 4 bits | 8*2 | DIP18 | LED panel display driver chip |
| CXLE88146 | 2 | 48 | 8*6 | - | Section 8, 6 digits | 8*2 | SOP20/DIP20 | LED panel display driver chip |
| CXLE88147 | 3 | 80 | 10*8 | Segment 10, 8 bits | 8 Segment 10 Bits | 8*3 | SOP28 | LED panel display driver chip |
| CXLE88148 | 3 | 64 | 8*8 | 8 Segment 8 Bits | Section 8, 6 digits | 4*2 | SOP24/QSOP24 | LED panel display driver chip |
| CXLE88149 | 2 | 128 | 8*16 | 8 Segments 16 Bits | 16 Segment 8 Bits | - | SOP28/SSOP28 | LED panel display driver chip |
| CXLE88150 | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 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 | - | Section 7, 4 digits | 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 segments 7 bits/5 segments 8 bits | - | SOP16 | LED panel display driver chip |
| CXLE88154 | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 10*2 | SOP28 | LED panel display driver chip |
| CXLE88155 | 3 | 70 | 10*7/13*4 | 10 segments 7 bits/13 segments 4 bits | Segment 7, 10 digits | 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 |
