CY8CMBR3108-LQXIT

Overview

The CY8CMBR3108-LQXIT is a register-configurable capacitive touch controller from the CapSense Express family, designed for applications requiring up to eight sensing inputs. It operates within a supply voltage range of 1.71 V to 5.5 V and supports an I2C interface with speeds up to 400 kHz. The device utilizes the CSD PLUS algorithm to achieve a signal-to-noise ratio greater than 100:1, ensuring high sensitivity and noise immunity. It features SmartSense Auto-tuning for dynamic performance maintenance and includes system diagnostics for fault detection. The component is housed in a 16-lead QFN package (3x3 mm) and functions across an industrial temperature range of -40 °C to +85 °C.

Feature Summary

• Register-configurable architecture eliminates firmware development requirements
• SmartSense Auto-tuning dynamically compensates for environmental variations
• Liquid tolerance prevents false touches caused by moisture or water droplets
• Integrated system diagnostics detect sensor shorts and capacitor faults

Applications

• Capacitive button interfaces replacing mechanical switches
• Linear or radial slider implementations
• Proximity sensing solutions with wake-on-approach capabilities

Procurement Notes

Verify the specific ordering suffix LQXIT to confirm the 16-QFN package and tape-and-reel packaging configuration. Ensure compatibility with the host I2C voltage levels and check for RoHS compliance documentation prior to integration. Confirm that the design accounts for the required decoupling capacitors on the VCC and VDD pins as specified in the datasheet electrical characteristics.

Selection Notes

Select this model when the application requires exactly eight capacitive sensing channels. Compare against the CY8CMBR3110 if ten buttons are needed or the CY8CMBR3106S if slider functionality is required alongside eight buttons. Consider the CY8CMBR3116 for designs needing sixteen inputs or proximity sensors. Evaluate power consumption requirements against the active mode current specifications per sensor.

Part Context

This component belongs to the Infineon CY8CMBR3xxx family of CapSense Express controllers. The family shares common core technologies including the CSD PLUS sensing algorithm and SmartSense Auto-tuning. Variations within the family primarily differ in the number of supported sensing inputs, slider capabilities, and available general-purpose outputs. The CY8CMBR3108 represents the mid-range option focusing on button and proximity sensing without slider support.

Replacement Considerations

Direct pin-compatible replacements within the same package include other CY8CMBR31xx variants such as the CY8CMBR3110-SX2IT, provided the additional input channels are not utilized. Cross-family replacements require careful review of pinouts and register maps.