Capacitive touchscreen line driver increases SNR

Improved SNR increases the robustness of the system in noisy environments and allows thicker cover lenses, reducing the number of samples and time required by the touch controller to scan large displays. Higher SNR also enables EMC resistance and advances multi-touch performance. This makes the MTCH652 suitable for demanding white goods, automotive systems and industrial controls including washing machines, refrigerators, dashboard infotainment, navigation controls and machine interface applications.

The simple high-voltage boost solution can improve robustness and increase the sensor sizes for touch controllers which support displays of up to 24". Wide input and output voltage range, in conjunction with the ability to daisy-chain the MTCH652, increases design flexibility.

Lillian Chao, President, Apex Material Technology, commented: “The addition of Microchip’s MTCH652 to our projected-capacitive electronics solution resulted in a more robust design that supports larger size displays up to 24” and facilitated passing 10V/m for radiated susceptibility testing and 10Vrms for conducted susceptibility testing (per IEC61000-4-3 Level 3 and IEC61000-4-6 Level 3). In addition, using the MTCH652 helped AMT achieve advanced features such as water immunity and gloved input. Also, AMT was able to easily integrate multiple MTCH652 chips to support larger designs.”

Available now in 28-pin QFN, SSOP and SOIC packages, the MTCH652 is available now. A variant that uses an external voltage boost for design flexibility and allows for up to 21 high-voltage drivers, the MTCH650 is also available now in the same packages.