AMC1211-Q1: Failsafe mode

Scarlett Cao

Part Number: AMC1211-Q1

Hi team,

My customer is doing the failsafe test where VDD1 drops below 2.5V and goes back to 5V. Two different phenomena appear during the tests: device either exits failsafe mode or remains at failsafe mode when VDD1 goes back to 5V. Could you help in analyzing what caused this difference? Thanks

CH2: VDD1

CH3: VOUTP

CH4: VOUTN

Thank you very much,

Scarlett

over 4 years ago

0 Tom Hendrick over 4 years ago

TI__Guru**** 172846 points

Hi Scarlett -

Is this question so good you had to ask it twice? Just kidding!

0 Alexander Smith over 4 years ago in reply to Tom Hendrick

TI__Mastermind 49831 points

Hi Scarlett,

It looks like the original post was moved to the deleted post forum - so we can discuss here.

What are the inputs tied to? Are they floating, or tied to GND1?

If floating, they could be drifting to some potential outside of the common-mode range.

0 Scarlett Cao over 4 years ago in reply to Alexander Smith

TI__Expert 3650 points

Thanks for your reply Alex!

0 Scarlett Cao over 4 years ago in reply to Alexander Smith

TI__Expert 3650 points

Thanks for your reply Alex! I've checked with customer, the inputs are tied to GND1.

0 Alexander Smith over 4 years ago in reply to Scarlett Cao

TI__Mastermind 49831 points

Hi Scarlett,

Thank you for confirming. I chatted with the design team and it looks like dropping VDD1 to this voltage - appears to be ~1V - can lead the fail-safe function to latch up. If the voltage drops all the way to 0, this issue should not be seen.

Is this occurring on multiple devices or just one?

Amplifiers

Amplifiers forum

AMC1211-Q1: Failsafe mode