MSP430FR2512: TIDM-CAPTIVATE-THERMOSTAT-UI and physical dimension

Hello Anber,

The size of the touch pad is 10mm x 10mm.

Here is part of the CapTIvate technology guide that talks about the mutual button size.

http://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/CapTIvate_Design_Center/latest/exports/docs/users_guide/html/CapTIvate_Technology_Guide_html/markdown/ch_design_guide.html#mutual-capacitive-buttons

The minimum pad size for reliable touch will depend on multiple factors in a design like the mechanical stack up, the overlay thickness, the PCB layout and the sensor tuning configuration. 

And to answer your question about the power consumption. Yes. The pad size can affect the power consumption.

For example, if your pad size is 10mm x 10mm and to get a reliable touch in your system you need to tune your sensor to 500 conversion count and the power consumption could be 6uA. But if you change the pad size to 5mm x 5mm, to get the same sensitivity you may need to increase the conversion count to 800 and the power consumption will increase with the conversion count. 

The power consumption also depends on multiple factors in your system like the conversion count, the conversion frequency and the scan frequency. Here are some test data we bench verified with the MSP430FR2633 on the CAPTIVATE-FR2633 processor module.

Thanks,

Yiding