Hello. This circuit is almost working but has one problem. Can someone offer some advice. Also if you see anything that could be improved let me know.
The power supply is single sided at +5.34 V. The Vin is a jack and will get plugged in from a different source and will be in the range of 0 to +5V. The voltage divider network then brings the input down to 0 to +3.3V. The diodes are there to protect against accidental over voltage and negative voltage. The opamp is running off of 3.3V power from the Teensy micro-controller. It is setup as a unity gain buffer and then outputs into the micro-controller pin 14.
When nothing is plugged into the Vin jack the micro-controller is reading some low volts jumping around. I imagine this is because the opamp + input is floating when nothing plugged into the jack? How can I fix this? I don't want to use a switching jack either.
Thanks!
The power supply is single sided at +5.34 V. The Vin is a jack and will get plugged in from a different source and will be in the range of 0 to +5V. The voltage divider network then brings the input down to 0 to +3.3V. The diodes are there to protect against accidental over voltage and negative voltage. The opamp is running off of 3.3V power from the Teensy micro-controller. It is setup as a unity gain buffer and then outputs into the micro-controller pin 14.
When nothing is plugged into the Vin jack the micro-controller is reading some low volts jumping around. I imagine this is because the opamp + input is floating when nothing plugged into the jack? How can I fix this? I don't want to use a switching jack either.
Thanks!