Does the RTC get powered when the teensy if switched off?

[georges_shed]

Hi all,

When the teensy is powered off using the push button input, does the RTC remain powered by the Vin or would you still need to connect VBAT?

 

[BriComp]

Which push button? The only button on the Teensy is a program button.

 

[georges_shed]

Ah. I mean when the teensy is powered down via the On/Off input.

 

[MarkT]

You need to explain your circuit I think, there is not on/off input defined to my knowledge.

From the T4 product page:

Real Time Clock/Calendar

The RTC is meant for keeping track of date & time. This timeruses a dedicated 32.768 kHz crystal, and continues to run whilepower is off if a 3V coin cell is connected to VBAT.

 

[georges_shed]

Hi Mark.
The On/Off input pin, as marked in the diagram. If you connect a push button to this input you can power the teensy down. I need to know whether the RTC will continue to be powered while plugged in (5v supplied to Vin) but in the powered down state.

 

[MarkT]

Oh yes, I'd never used that - I don't know the answer.

 

[jmarsh]

Just check the schematic, VBAT is tied (via diodes) to the output of the 3.3V regulator (which is apparently redundant anyway since VDD_HIGH_IN is internally connected to VDD_SNVS_IN).

 

[defragster]

On/Off input pin

If USB power is maintained on the Teensy so that the ON/OFF button works - the RTC time is also maintained with or without battery.