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SN74HC245: Back Powering Input

Part Number: SN74HC245

Customer has SN74HC245 with an input being driven when the board is unpowered.

Just wanted to confirm my recommendations to the customer and get your inputs:

Basically your back powering the board via the input.  That’s a common issue.

The SN74HC245 absolute maximum input clamp current is 20 mA, that’s what I’d be concerned with.  TI offers logic devices with Ioff protection such as SN74LVC245A for this type of application.  Otherwise you could insert a current limiting resistor between the devices.

Let me know if you concur.