TSC2046E lowest power mode with PENIRQ available

David DeB

Other Parts Discussed in Thread: TSC2046E

Hello,

we would like to use the TSC2046E PENIRQ interrupt to enable the main load switch of our system. TSC2046E would be the only chip always-on and it's power consumption while waiting for a first touch would thus be very important. Which of its power saving modes would allow for the PENIRQ to be active while saving most energy ? In other words, is the PENIRQ interrupt enabled when in the "10µA Power-Down Mode" for example ? We don't need X/Y positions but simply detect the touch to wake everything up.

Electrical characteristics is page 4 of the datasheet : www.ti.com/lit/ds/sbas510/sbas510.pdf

Thank you, David

over 10 years ago

0 Andy Liu (BMS) over 10 years ago

TI__Guru 52115 points

Hi David,

I will take a look at your issue and get back to you soon.

Andy

0 Andy Liu (BMS) over 10 years ago in reply to Andy Liu (BMS)

TI__Guru 52115 points

Hi David,

Here are my comments:
a) Take a look at this reference firmware first : e2e.ti.com/.../3138.reference-firmware-for-tsc2046tsc2046e

b) Based on your requirements, I think you just have to do the steps below:
1) Send "CMD_ENABLE_PENIRQ" (its definition could be found in the reference firmware above) to the TSC2046E via SPI when the TSC2046E device is initialized and enable the interrupt pin of the host MCU.
2) Once any touch is detected by the TSC2046E, the /PENIRQ pin will become low and the host MCU will be notified.
3) In the interrupt handling routine, send "CMD_ENABLE_PENIRQ" again via SPI to command the TSC2046E to enable the /PENIRQ pin and power down the internal ADC. (Maybe this step is not necessary).

Andy

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TSC2046E lowest power mode with PENIRQ available