Disable Clamping diodes MSP430 GPIO

Hi,

We don't have such function to disable clamping diodes. 

The clamping diodes are for overvoltage protection. Why do you want to disable them?

I have one end of coil connected to GND and another to a GPIO. I wanted the coil to completely disconnect, like it was physically disconnected. Making the GPIO as ADC input does not work either. Is there any other ultra low current external component you can suggest that will physically disconnect the coil?

Thanks,

Jay

Hi Jay.
What is the maximum induced voltage on the coil?
If it is less than the supply voltage of the MCU you can switch both ends and no significant current will flow through protection diodes.

Best regards,
Tomas

Hi Tomas,

The Vcc is 3volts and the maximum induced voltage spike is around 18.3 voltage when magnet moves over it. But this is a small air core coil with 10K turns of very fine magnet wire. The clamping diodes makes coil slow down the magnet due to Faraday effect. I want to totally disconnect the one of the coil wires and connect it back on demand and then energize the coil when needed.

Thanks

An open drain MOSFET lacking a body diode might be just the thing. 2N4351 or some such with a suitable breakdown voltage.

As far as I know, there are always intrinsic diodes between the drain/source and the substrate (body) in MOSFETs. I'm not sure there is a simple transistor connection that allows you to switch both positive and negative voltages without bias. There are "beyond-the-rails" analog switches that have an internal bias generator and would meet the requirements, but they are not very low power.

Thank you Tomas. I will try that.