TPS3890 to enable/disable TPS62743

Jon Snow

Other Parts Discussed in Thread: TPS62743, TPS3831

For a li-ion battery powered system, would it be recommended to use TPS389033 to monitor the input voltage of TPS62743 and enable/disable the operation of TPS62743 by connecting the __RESET pin of TPS389033 with the EN pin of TPS62743?

over 7 years ago

0 Nicolás Román over 7 years ago

TI__Intellectual 960 points

Hi Jon,

Assuming you want to use the the TPS389033 to monitor the li-ion battery (so the voltage does not go under the recommended V min) and you are operate the parts with in the operating conditions, you can control the EN input of the TPS62743 with the /RST output.

Remember to use a pull-up resistor on the /RST output of the TPS389033, since it is an open-drain output.

Best regards,

Nicolás

0 Jon Snow over 7 years ago in reply to Nicolás Román

Prodigy 60 points

Hi Nicolás,

Thanks for your answer. Yes, I'm planing to add 1MOhms pull-up resistor on the /RESET output of TPS389033.

I have a slide switch for power on/off the device, should I connect the slide switch to the SENSE pin or to the /MR pin? The switch will drive SENSE to GND when off and to the VCC of the battery when on. I'm not sure if I should connect the on/off switch to /MR instead.

Any advice is welcome.

0 Jon Snow over 7 years ago in reply to Jon Snow

Prodigy 60 points

7242.schematic.pdf

This is the schematic with the on/off slide switch connected to /MR. Would that be better than connecting the switch to SENSE pin?

0 JCHK over 7 years ago in reply to Jon Snow

TI__Mastermind 43610 points

Hi Mike,

S1 connected to the /MR pin as shown is the intended use of the /MR pin. Also, if the customer does not mind a push-pull reset output, another option is the TPS3831 is a much lower Iq reset IC for portable applications.

Regards,

0 Jon Snow over 7 years ago in reply to JCHK

Prodigy 60 points

Thanks John. The TPS3831 /RESET pin should be connected directly to EN pin of TPS62743 with no pull-up resistor, correct?

0 Nicolás Román over 7 years ago in reply to Jon Snow

TI__Intellectual 960 points

Hi Jon,

Yes, the TPS3831 /RESET output has a push-pull output drive, what means that you don't need pull-up resistor.

Best regards,
Nicolás

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TPS3890 to enable/disable TPS62743