The power consumption of Low-Power Capsense Design with multiple buttons.

[JuIn_1625121]

Hi,

The customer considers to use Low-Power CapSense Design As described in AN210998.

If he needs three buttons, what is the power consumption?
I have two ideas.

1)

2)

Which is correct?

I think that this may be misunderstood.
Please teach the correct answer.

Best Regards,

Inoue

[ShanmathiN_06 · Accepted solution]

Hi,

Both the methods are correct.

Let us assume the following:

Scan time (active power mode) for 1 button = ts1

Process time (active power mode) for 1 button = tp1

Current in active power mode = Isp

Then, for 3 buttons, you could either split it as scan button1, process button1 etc.,. or as scan the three buttons and then, process the three buttons. (i.e) ts1, tp1, ts2, tp2, ts3, tp3 or ts1, ts2, ts3, tp1, tp2, tp3.

It depends on your firmware implementation.

Thanks,
Shanmathi

[JuIn_1625121]

Hi Shanmathi,

Thank you for your answer.

I understood.

Best Regards,

Inoue