Hi:

I'm working with a sensor that's specified to have an output between 2.4 
and 2.6 VDC (Vcc +5 V) and would like to amplify it's DC output.
Since the signal output is on the order of a few millivolts an 
adjustable voltage reference is needed to keep the op amp swing between 
the rails.  I've been using a couple of fixed resistors and a pot for 
this but would like to use the PWM output from a 16F88 and some type of 
circuit that would provide the 2.4 to 2.6 VDC reference signal that 
would not change (the actual value would be established once during 
calibration).  When the PWM output was a constant +5 volts the circuit 
output would be +2.6 VDC and when the PWM output was a constant 0 volts 
the circuit output would be +2.4 VDC.

Is there a circuit that does this?  Since op amps come in dual and quad 
configurations one or two would be available for this function.

Thanks,

Brooke Clarke, N6GCE

-- 
w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml
http://www.precisionclock.com

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist