TPS62290 - EN > Vin?

Q: TPS62290 - EN > Vin? by 574

A question has come up regarding the enabling of the TPS62290.  I see a spec in the datasheet that says that the enable needs to be below VIN + 0.3V.  That makes sense to me but I have two questions:

1. Can you describe what happens if the spec is violated?

2. Can you recommend a series resistor on the enable to prevent this?


A: Re: TPS62290 - Vin Specs by 1090425

If this spec is violated, the device could be damaged and draw excessive current.

The best way to not violate this spec is to use a voltage divider on the signal driving the EN pin.  Another option is a resistor followed by a zener diode to clamp the voltage.  The zener must clamp the voltage below the abs max rating to guarantee proper operation.

If the absolute maximum ratings are exceeded, device operation is not guaranteed.  You need to keep the voltage on EN between 1V and Vin to register a logic high (page 3 of datasheet).  Simply limiting the current is not a valid solution since the voltage still exceeds the absolute maximum rating.

This also applies to the very similar TPS62240, TPS62260, TPS62560, and TPS62590.