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By bob-bob
#196907
I'm looking for some generic information regarding how to set up the BOB-09816. My understanding is the following:
VCC = +5V power source
GND = ground from power source + ground from input + ground from output
IN = input signal
OUT = amplified output signal

I've hooked up the board according to the above definitions. After sweeping through a range of voltages on the input (IN) the output (OUT) always will read ~2.5 V. My understanding of how the chip is supposed to work is that the input signal will be amplified by the gain (gain = 100 out of the box). Through this logic: IN = 0.1V --> OUT = 10V. Can someone 1) explain how the board is really supposed to work 2) possibly explain how I can get the board to work like my example?
By n1ist
#196914
The output can't go above Vcc (actually, it can get to 100mV of Vcc or Gnd) so you won't get 10V out. Also, the circuit is AC coupled (there are capacitors at the input and between the two stages). It will amplify a varying signal (say, from a microphone or photodiode) but not a DC signal.
/mike
By bob-bob
#196916
I guess I don’t quite understand why it wouldn’t amplify a dc signal. I can change the input voltage from .01 to 1V and the output is always 2.5 V.