CXHA31133 is a high-performance and highly reliable touch button control integrated circuit that has the ability to communicate with external main controllers via I2C, and is equipped with a communication control module for driving external display chips such as CXLE88142 and CXLE88155. This chip has extremely high integration and can achieve precise touch button detection with very few external components. It is widely used in scenarios that require human-computer interaction, such as induction cookers, smart home panels, and industrial control interfaces.
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[ CXHA31133 ]"
CXHA31133 is a high-performance and highly reliable touch button control integrated circuit that has the ability to communicate with external main controllers via I2C, and is equipped with a communication control module for driving external display chips such as CXLE88142 and CXLE88155. This chip has extremely high integration and can achieve precise touch button detection with very few external components. It is widely used in scenarios that require human-computer interaction, such as induction cookers, smart home panels, and industrial control interfaces.
1、 Main features and advantages
CXHA31133 has the following core features:
1.1. Wide voltage operating range：2.7V～5.5V， Suitable for various power environments.
1.2. Automatic calibration functionDynamically adjustable benchmark values to adapt to environmental changes and improve detection stability.
1.3. Dual mode operationSupports sleep mode and normal working mode, effectively reducing power consumption.
1.4. Built in driver moduleIt can directly drive the active buzzer and external display chip CXLE88155, reducing the complexity of external circuits.
1.5. Strong anti-interference abilityCapable of withstanding voltage fluctuations and electrostatic interference, enhancing system reliability.
1.6. Standard I2C interfaceSupport standard I2C communication method, 100kHz communication rate, convenient for communication with the main control MCU.
1.7. Adjustable sensitivityFlexibly adjust touch sensitivity through an external capacitor (0-25pF).
2、 Pin function and electrical characteristics
2.1 CXHA31133 adopts SOP16 packaging, with clear pin definitions:
2.1.1)Key1~Key88-way touch button input port, grounded when not in use.
2.1.2)SCL、SDAI2C communication clock and data cable.
2.1.3)STB、CLK、DIOUsed to drive control signals for external display chips.
2.1.4)BZActive buzzer driver output.
2.1.5)VDD、GNDPositive and negative poles of the power supply.
2.2. Its electrical characteristics are as follows:
2.2.1)Working voltage: 2.7V– 5.5V
2.2.2)Working temperature: -40 ℃ to+85 ℃
2.2.3)Input/output current capability: up to 20mA (VDD=5V)
2.2.4)Buzzer driving current: maximum 50mA (VDD=5V)
2.2.5) Switch characteristics
3、 I2C Communication and Register Configuration
CXHA31133 serves as an I2C slave device with addresses 0xA0 (write)/0xA1 (read). The main control MCU can read button status, send display data, control the buzzer, and enter sleep mode through I2C.
CXHA31133 provides a slave I2C communication interface that supports bus protocols compatible with standard I2C. The communication address of CXHA31133 is 0xA0. The main control can read touch button status information and also write display data for driving CXLE88155 and buzzer data. The speed of I2C supports standard mode 100KHZ.
After reading the key information, wait for at least 10ms before reading the key information again. Write display address and display data at least 1ms apart, and write other data at least 200us apart before reading or writing data to CXHA31133 again.
3.2.Main register functions:
External MCU can access registers through I2C, read touch button status information, write display commands and data, drive buzzer to emit sound, and enter and wake up sleep mode. The data written by the external MCU through I2C is forwarded by CXHA31133 to the external display chip. CXHA31133 Register Function Description:
3.2.1)0xBDDisplay mode settings (segment configuration)
3.2.2)0xBE: Data read/write and address increase mode settings (default 0x40)
3.2.3)0xC0~0xCDDisplay Content Data Register
3.2.4)0xBFDisplay switch and brightness adjustment (8-level adjustable)
3.2.5)0xCEBuzzer drive time setting (40ms/level, 255 levels in total)
3.2.6)0xCFSleep mode control
3.2.7)0xF0Key status reading register
4、 Detailed explanation of intelligent functions
4.1. Maximum button time protection
The chip has a built-in 64 second timeout protection mechanism to prevent system abnormalities caused by accidental touch or prolonged pressing. It will automatically reset and recalibrate after timeout.
4.2. Automatic calibration mechanism
After power on initialization, the chip automatically calibrates the reference value regularly to adapt to changes in environmental temperature, humidity, voltage fluctuations, etc., ensuring the accuracy of touch detection.
4.3. Sensitivity adjustment
Users can flexibly set touch sensitivity by adjusting PCB electrode size, panel material, or external capacitance value (0-25pF) to adapt to different application scenarios.
4.4. Register Description
External MCU can access registers through I2C, read touch button status information, write display commands and data, drive buzzer to emit sound, and enter and wake up sleep mode. The data written by the external MCU through I2C is forwarded by CXHA31133 to the external display chip. CXHA31133 Register Function Description:
5、 Typical Application Circuit
CXHA31133 can be paired with CXLE88155 display chip and active buzzer to form a complete human-machine interaction system. Typical application circuits include:
5.1) Touch button input interface (each Key pin is connected to a capacitor to ground)
5.2) I2C pull-up resistor (10kΩ)
5.3) Display chip control lines (STB, CLK, DIO)
5.4)Buzzer driver circuit (series 1kΩ); Resistance)
6、 Packaging and mechanical specifications
The chip is packaged in SOP16 and has a compact size (10.0mm x 6.2mm), suitable for applications with limited space. Please refer to page 9 of the data manual for detailed mechanical dimensions.
Conclusion
CXHA31133 is an ideal choice in the field of touch control due to its high integration, powerful anti-interference ability, and flexible configurability. This chip can provide stable and reliable solutions for home appliance control, industrial panels, and intelligent device interaction. For further information on its application design or technical support, please contact our engineering team.
Related Products
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| model | detection method | detection distance | Output configuration | Drive Type | remark |
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| model | Working Voltage | Port withstand voltage | PWM cycle | package form | |
| CXHA31126 | 2.4V-5V | 6V | 6.13ms | SOT23-5 | vibration sensor |
| CXHA31127 | 2.4V-5V | 6V | 4.87ms | SOT23-5 | vibration sensor |
| CXHA31128 | 2.8V-9.5V | - | - | SOP8/SOT23-6 | vibration sensor |
| CXHA31129 | 2.7V-5.2V | - | Adjustable duty cycle | SOT23-6/DFN6H | vibration sensor |
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| CXHA31131 | 2.7V-5.2V | - | I2C control | MSOP10/SSOP10/QFN3*3 | vibration sensor |
| model | Working Voltage | Number of interfaces | Number of driving buttons | package form | |
| CXHA31132 | 2.2V-5.5V | twoThefour | eight | SOP16 | Touch sensor |
| CXHA31132S | 2.2V-5.5V | two | 8 (Supports slider function) | SOP16 | Touch sensor |
| CXHA31133 | 2.2V-5.5V | two | eight | SOP16 | Touch sensor |
| CXHA31134 | 2.8V-3.6V | four | twenty-eight | QFN40 | Touch sensor |
| CXHA31135 | 2.8V-3.6V | four | thirty-six | QFN48 | Touch sensor |
