TPS74401 pre-bias capable?

George Biner (Arrow)

Hello: my customer has a question:

"When enable is pulled low on TPS74401KTWT, is the output tri-stated? I have an application where I may use the output of this LDO or the output of another power supply and want to make sure that there isn’t a problem with this LDO if I have it disabled and apply voltage to its output."

regards, G Biner

over 12 years ago

0 Darwin Fernandez over 12 years ago

TI__Mastermind 41760 points

Hi George,

What voltage will be at the output? As long as the abs max rating is not violated in your application (VOUT<VIN+0.3), the device should not be damaged.

Regards,

Darwin

0 George Biner (Arrow) over 12 years ago in reply to Darwin Fernandez

Intellectual 705 points

thanks, I will tell the customer to stay in the abs max ratings.

You say the device will not be damaged, that's good, but what does the output look like when the chip is disabled? High Z? Or will it sink current?

0 Darwin Fernandez over 12 years ago in reply to George Biner (Arrow)

TI__Mastermind 41760 points

Hi George,

Yes, this device can sink current when disabled. Checking this in lab, putting 5V at the output yielded 10mA which yields about a 500Ohm active pull down resistor (the current throught the resistor divider is much less than 10mA so I did not take the resistor divider into account)

Regards,

Darwin

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TPS74401 pre-bias capable?