Post by thread:high res adc or similar -Reply

Peter, Try an op-amp prescale with gain of 25. The 200 mV X 25 = 5V and 10uV X 25 = 250 uV. If you don't want to dither the signal as mentioned in another post you'll need at least a 15 bit converter but with the prescale you'll have a 5V signal to work with. Of course you may have left out info that would preclude this as a viable solution so YMMV - -Mark >>> Peter Grey <spam_OUTmartechTakeThisOuTOZEMAIL.COM.AU> 7 March 1997 8:57 am >>> I wish to use a pic to determine a signal which has a resolution of 10 microvolts in 200 millivolts. It also has a requirement for any component to be in a very small package (ie surface mount and preferably in an 8-pin SOIC). I can get a 16 bit ADC but the range is usually that of the supply rail to ground. If I was to look at 10 microvolts in 5 volts then a 20 bit ADC would be needed. As you can see I would need serial I/O for the digital side. The ideal solution would be the LTC1298 but with a resolution of 20 bits. Any ideas would be appreciated. TIA, Peter Grey Neosystems Australia