Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
R37 is a very important part of the circuit since it and R42 set the input voltage of the opamp, then since the opamp has a gain of 1 the output voltage of the opamp is also set to be the same as the input voltage.
try this:
apply voltage divider at the + input of the op amp V+ = ...
assuming a perfect op amp, V- and output = V+
combine R25 and R28 to one equivalent resistor
assuming Vo is open, apply voltage divider (Vf, R21, V+ and equivalent R25-R28)
when you have Vo = ..., replace V+ with what you got above
follow the rules of algebra
expand everything so there are no parenthesis and no fractions
put all terms with R37 on one side of =, everything else on the other side
factor out R37 and divide
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.