LM2904B-Q1: VCC or VSS status when input signal comes in to input pin and Power line disconnection status.

Lenny Lee

Part Number: LM2904B-Q1

Tool/software:

Hi Team,

Customer is asking that any voltage value would be measured at VCC and VSS pins when All power lines are disconnected(or off) but input signal comes in over 12V at V+ and under -12V at V- pins. (in normal operating range)?

And those are ok to use without any damage in normal power-on operating condition?

BR.

Lenny Lee.

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 317450 points

See the absolute maximum ratings; they allow some voltages above V+.

There are diodes from V− to the input pins. You have to ensure that no current can flow, or that it is limited.

0 Ron Michallick over 1 year ago

TI__Guru**** 165376 points

Lenny,

Positive voltage at input pins will not cause input current. Positive voltage at output pins will pass to VCC

Negative voltage at input pins or output pins will pass to VSS.

0 Lenny Lee over 1 year ago in reply to Ron Michallick

TI__Intellectual 1130 points

Hi Ron,

Thanks for feedback.

It means, positive input at V+ will not go to VCC+ but Negative input at V- will go to Vcc-. is that correct?

0 Ron Michallick over 1 year ago in reply to Lenny Lee

TI__Guru**** 165376 points

Lenny,

Correct, positive input at [+] or [-] will not go to VCC+. Negative input at [+] or [-] will go to Vcc-.

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LM2904B-Q1: VCC or VSS status when input signal comes in to input pin and Power line disconnection status.