TPS27SA08-Q1: Floating voltage on input side when switch is disabled

Gerard Cirera

Part Number: TPS27SA08-Q1
Other Parts Discussed in Thread: TPS1HTC30-Q1

Tool/software:

Found the high side switch to have a floating voltage of 1.65V on the input side when it is disabled. There is also nothing connected on the output side.

Is this normal? Can someone confirm that this is the intended function?

It will likely not cause issues in our design but is still odd to see, especially since our other high side switches (TPS1HTC30-Q1) do not have this happen.

Thanks!

8 months ago

0 Patrick Shalton 8 months ago

TI__Mastermind 34190 points

Hi Gerard,

Thanks for reaching out, can you confirm if when you see this behavior, the VBB signal is floating (measured at 1.65V) and the output is floating? Are any of the digital input pins high?

Thanks,

Patrick

0 Gerard Cirera 8 months ago in reply to Patrick Shalton

Prodigy 45 points

DIAG_EN is high, EN1 low, EN2 floating, Latch floating, SEL1 and SEL2 pulled to GND

Now seeing 1.2V on VBB, when last week it was 1.65V

+1 Patrick Shalton 8 months ago in reply to Gerard Cirera

TI__Mastermind 34190 points

Hi Gerard,

This looks to be some weak leakage or diode path inside the device from the digital input(s) to VBB, but this doesn't pose a risk to the device as the digital pins can be powered independently of VBB.

Thanks,

Patrick

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TPS27SA08-Q1: Floating voltage on input side when switch is disabled