Vybrid tamper current and VBAT

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Vybrid tamper current and VBAT

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juandiaz
Contributor II

Hello,

I am using an external tamper and I set a pull-up resistor connected to VBAT. The tamper circuit is normally tied to ground, and if it is opened, the pull-up issues the tamper signal to VBAT voltage. The VBAT voltage is around 3V.

I mounted a 10k pull-up resistor, the tamper event is issued. However, when I mount a 100k pull-up resistor, the tamper event does not work. I would like to optimise the maximum resistor that makes the tamper work.

My question is which resistor fits the best to get a tamper trigger.

Regards,

Juan.

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3 Replies

851 Views
Yuri
NXP Employee
NXP Employee

Hello,

  The previous value of 10 k was quite reasonable. 100k is very high

to provide needed voltage level.

Have a great day,
Yuri

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851 Views
juandiaz
Contributor II

Hello Yuri,

My idea is to minimise the current of the pullup. Do you know which resistance value is necessary to make the tamper work? Or which minimal current is necessary to inject in the tamper0 input?

Regards,

Juan.

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851 Views
Yuri
NXP Employee
NXP Employee

Hello,

  Minimal current / resistance values for the tamper are not specified. Sorry.

Regards,

Yuri.

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