Question
I can successfully use the AD8555 in a differential configuratuion.
However, my application is better suited to a single ended configuration.
According to the AD8555 General Decsription, the device can be used with single
ended sensors. How can this be done without the 'short wire fault detection'
feature disabling the output?
Answer
Because of the Short wire fault detection, it isn't possible to ground the VNEG
pin and drive only the VPOS pin. The input voltage has to be between 0.6 and
3.8V. However it is possible to use single ended, ground referred sensors by
operating the AD8555 from +/-2.5V supplies. If the sensor is floating (i.e. not
ground referred) then you can simply bias-up the VNEG terminal and the sensor's
negative terminal to midscale using a potential divider.