Hi Joe, thanks for the response.

2011-01-07T16:37:58.930-05:00

Hi zbaker, Yes, the single-ended to differential a...

2011-01-06T15:49:16.540-05:00

Hi zbaker,
Yes, the single-ended to differential amplifier has a gain of 2, and the A/D has a range from -0.512 to +0.512 volts, so the input signal has a range of about 0.5 volts: -0.23 is a 0x00 output and 0.33 is 0xff. It's not quite centered on zero due to the feedback circuit.
The equation should be Vcm=Vcc*0.3. The 0.3 factor comes from the A/D converter spec sheet: its input signals are supposed to be biased around 0.3*Vcc, or about 0.9 volts with a 3 volt supply. Vcm is the voltage on the common mode input pin of the amplifier; it's used to bias the amplifier outputs so they are centered on 0.9 volts and keep the A/D happy.
Hope that helps.
Joe

Hi Joe, What is the input range on your A/D front...

2011-01-05T18:54:19.583-05:00

Hi Joe,
What is the input range on your A/D frontend? I see you have a 2x gain in your single ended to double buffer, but I'm not sure how your Vcc=Vcm+0.3 limits or improves the range. ?

Comments on Sensicomm LLC - Signals, sensors, comms: MHZ100Q - on sourceforge

Hi Joe, thanks for the response.

Hi zbaker, Yes, the single-ended to differential a...

Hi Joe, What is the input range on your A/D front...