TPS3838: Max sink current on RESET# pin?

Jordan Lippitt

Part Number: TPS3838
Other Parts Discussed in Thread: TPS3808

Hi,

I am using the TPS3838 as an open-drain voltage supervisor for a Bluetooth module's VCC.

I also have the push-pull output 'PROG_RSTn' from a TLC555QDRQ1 connected to the same node. There is a possibility where PROG_RSTn drives high and RESETn open-drain pin drives low and that would short 3.3V to GND. I want to change R14 from 0 ohms to a value that would limit the current if this situation were to arise. Do you know what is the max operating sink current that the RESETn pin can handle?

over 1 year ago

0 Patrick Shalton over 1 year ago

TI__Mastermind 18320 points

Hi Jordan,

Thanks for reaching out! On page 5 of the TPS3838 datasheet, it states that the recommended pullup resistor value for the open drain output is V_pullup / 50μA. Thus, I believe the maximum current sink is 50µA, and a wise design choice would be to allow for 25µA from each of the 3.3V input and PROG_RSTn to consider the event when only the TPS3808 output drives low.

Thanks,

Patrick

0 Jordan Lippitt over 1 year ago in reply to Patrick Shalton

Prodigy 20 points

I somehow missed table 7.3 calls out 5mA max on RESET# pin

Power management

Power management forum

TPS3838: Max sink current on RESET# pin?