arefeidi
Member level 4
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amplifier coupling
Hi,
I'm building up a differential amplifier like this one: http://www.ecircuitcenter.com/Circuits/adcin_diff_se/adcin_diff_se1.htm (With Vref=0V, so no additional Offset voltage)
Vpos is an AM-modulated 50kHZ sine wave, Vneg is exactly the same signal with 180° phase shift. Someone said to me that I need to have coupling capacities at the input, though - I don't understand why.
If there is a DC offset in the input signals, doesn't it get removed by the differential amplifier anyway? Vout=(R2/R1)*Vpos-Vneg
So what would be the reason to add coupling capacities at both inputs?
Hi,
I'm building up a differential amplifier like this one: http://www.ecircuitcenter.com/Circuits/adcin_diff_se/adcin_diff_se1.htm (With Vref=0V, so no additional Offset voltage)
Vpos is an AM-modulated 50kHZ sine wave, Vneg is exactly the same signal with 180° phase shift. Someone said to me that I need to have coupling capacities at the input, though - I don't understand why.
If there is a DC offset in the input signals, doesn't it get removed by the differential amplifier anyway? Vout=(R2/R1)*Vpos-Vneg
So what would be the reason to add coupling capacities at both inputs?