C col_implant New Member Nov 27, 2007 #1 Maybe this is a silly question.... Is it possible to apply a level shift to a transimpeedance amplifier? I searched google and only got patents as results... this tells me no!
Maybe this is a silly question.... Is it possible to apply a level shift to a transimpeedance amplifier? I searched google and only got patents as results... this tells me no!
J jeg223 New Member Nov 27, 2007 #2 you can pull the input signal up to whatever level you want. It works like a linear combination circuit. If you use a voltage source make sure the input resistor is equal to the feedback resistor so your offset gain is unity.
you can pull the input signal up to whatever level you want. It works like a linear combination circuit. If you use a voltage source make sure the input resistor is equal to the feedback resistor so your offset gain is unity.
C col_implant New Member Nov 27, 2007 #3 I was thinking of using a PIC Comparator reference voltage, output directly to V+ input. The currents I'm measuring are quite small (100pA min). Could noise on the reference be a problem? Perhapps decoupling required?
I was thinking of using a PIC Comparator reference voltage, output directly to V+ input. The currents I'm measuring are quite small (100pA min). Could noise on the reference be a problem? Perhapps decoupling required?
J jeg223 New Member Nov 27, 2007 #4 Don't you have to worry about the input bias currents at that point?
C col_implant New Member Nov 27, 2007 #5 Wel input bias is of the order of 1pA, quite a good amp we are using
J jeg223 New Member Nov 27, 2007 #6 In that case, Vout= V+ - Rf* Iin Although bias current and offset voltage may make life miserable. Last edited: Nov 27, 2007