I/O protection digital potentiometer

Hello

I am playing around with a digital potentiometer (Ti TPL0501) and got it all working as I wish. It is going to replace a regular pot in a control unit in a automotive environment. In the future my idé is to make a product of this maybe.

The digipot is rated for +-5mA on the pot pins and that is OK as the max current is 2.5mA max and 0-5V. I guess (potted PCB) the pot in the control unit is part of a voltage divider. The wiper goes to ground and one side of the pot goes into the control unit.

But how can I protect the digipot pin from over voltage/current?

If lets say the user by accident connects the the digipot output to +12 or similiar?

I cannot use a series resistor to limit current as this would upset the potentiometer resistance?

Datasheet www.ti.com/lit/ds/symlink/tpl0501-100.pdf

Regards

The wiper goes to ground and one side of the pot goes into the control unit.

Uh, no. When the wiper is near or at the source voltage end of the pot, it will result in uncontrolled current and the destruction of the pot.

Please post a schematic of how you have this wired, hand drawn is fine.

You could use a zener clamping circuit to protect overvoltage. Simple, and cheap.

There are also over current protection ICs you can use.

dustin02rsx: You could use a zener clamping circuit to protect overvoltage. Simple, and cheap.

Bad advice. Schottky claming diodes (to VCC and ground) could be better. They also protect when the device is off (zeners do not). Need to see the whole circuit to know what sort of protection would be best. Leo..