Power On Reset IC

Alex N

Other Parts Discussed in Thread: TPS3840, TLV840

I am working on implementing a system level reset sequence upon power up. When the voltage reaches a set threshold, the reset circuit outputs a logic LOW.

I have tried several of the TI model chip-sets including the TPS3840 and TLV840 with no luck.

Which IC should I be using for this application?

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 277220 points

I do not understand what you mean with "no luck". What is the problem with these devices?

0 Alex N over 3 years ago in reply to Clemens Ladisch

Prodigy 240 points

These devices will not output a logic low upon initial startup, which is what I need for my system.

0 Clemens Ladisch over 3 years ago in reply to Alex N

Guru 277220 points

It is not possible to actively output anything when the supply voltage is too low (< 0.7 V for the TLV840). But at such low voltages, other devices will not yet start up.

Do you have some device that does something wrong at 0.7 V?

0 Alex N over 3 years ago in reply to Clemens Ladisch

Prodigy 240 points

I am wanting a TI equivalent to something like the Microchip MCP102 that waits till the system voltage reaches a certain level at startup and then outputs its logic signal.

All I can currently find from TI is voltage supervisors that are made to work during system operation, and not at initial system startup.

0 Ben C over 3 years ago in reply to Alex N

TI__Mastermind 39895 points

Hi Alex,

We have TLV809E which has very similar performance as the MCP102. If there are no further questions, please click on "resolved" to close the thread. Good luck to you!

Ben

0 Ben C over 3 years ago in reply to Ben C

TI__Mastermind 39895 points

Hi Alex,

Are there any updates? If not, please click on "resolved" to close the thread. Thanks!

Ben

0 Alex N over 3 years ago in reply to Ben C

Prodigy 240 points

I apologize, but this issue was my user error.

I neglected to place a pull-up on the output line, thus I could not see the initial startup pulse

0 Ben C over 3 years ago in reply to Alex N

TI__Mastermind 39895 points

Hi Alex,

Glad to know that your problem was resolved. Good luck to you!

Ben

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Power On Reset IC