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

Motoyasu Hattori

Genius 9705 points

Part Number: LM2903B

Hi,

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,
M.HATTORI.

over 2 years ago

0 kai klaas69 over 2 years ago

Guru 140200 points

Hi Motoyasu,

I would do it this way:

Kai

0 Joe Vanacore over 2 years ago in reply to kai klaas69

TI__Genius 13700 points

Hi Kai,

Thank you for your support on this as always.

Hello M.HATTORI.

Thank you for your question. Please let me know if you have any questions about Kai's suggestion.

Best Regards,

Joe

Applications Engineer

Linear Amplifiers Business Unit | Comparators Product Line (CMPS)

All information in this correspondence and in any related correspondence is provided “as is” and “with all faults”, and is subject to TI’s Important Notice (http://www.ti.com/corp/docs/legal/important-notice.shtml)

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