Multisim and Ultiboard
AD8422 instrumentation amplifier troubles in MultiSim - new to multisim/circuit design
Hello all,
I am diving headfirst into analog circuit design with very little experience to keep me afloat... If there is an expert out there that could help me out I would be most appreciative.
The goal: amplify the 0-100mV signal from a pressure tranducer to 0-10V (sounds simple enough)...
The issue: when attempting to model this circuit in MultiSim the AD8422 instrumentation amplifier does not respond as I would expect. In the snippet below, I have (attempted) to model the effective circuit. The AD8422 in-amp is driven by a +12V DC source, the transducer output is simulated by the 0.1V DC source, and the gain resistor is selected to yield a gain for 100 per the table in the datasheet.
With this circuit, I would expect the amplifier to spit out something close to 10V, but as you can see, the output is only about 500mV. Does anyone know what I'm missing here? Hopefully I'm not completely off the mark...
Best regards,
Jesse Butler
Jesse,
Although it is described as a "rail to rail" amplifier, the data sheet specifies the input common mode ragns as not including the most negative power supply.
Lynn
