This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM2903B: Output status under Vcc<2V (during power-up).

Part Number: LM2903B


Could you please let us know the output pin status on LM2903BIDR under Vcc<2V.

My customer considers the following circuit.

LM2903BIDR's pin condition is as follows:

  • Vcc : 5V line from DC/DC
  • IN+ : Divided resisters on 5V line from DC/DC
  • IN- : LOW (Pull-down) during 5V power-up
  • OUT : connected with /SHDN (internal pull-up on 2.7V)


Under the above case during power-up on 5V line, after Vcc>2V, output of LM2903B is open and /SHDN pin is 2.7V.   How about Vcc from power-up (0V) to 2V?   Is it possible to output low from LM2903B under Vcc<2.0V condition?   Please advise us.

We understand LM2903B is unknown status under Vcc<2.0V.  However if it is possible to output low on LM2903B, this system can not wake up, because TPS26631 is shutdown and power is OFF if /SHDN is low (under 0.8V).  So please support us.

Thanks and best regards,