input 5,0 V output 5,-5V

Status
Not open for further replies.
F

firsttimedesigning

Full Member level 1
Joined
Jul 4, 2007
Messages
97
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
2,241
I want to make a circuit that will produce 5V when the input is 5V and produce -5V whent he input is 0V. Does such circuit exist? I have tried several ways, but none of them worked. So if there is any suggestion, please post it. Thanks
 

Thank you for the reply. The circuit works. I can see that when Vin is 0V, the circuit functions as an inverting amplifier. However, I dont get how does the circuit work when it's Vin is 5V. Please explain it to me, thank you. What I really dont get it, why is R/2 resistor necessary?
 


when Vin is 5V, theOPAMP's Vin- will be 5V,too.
so there is no current at R.
No current means the Vout must equal Vin-, so the output is 5V.
 

But, what is the necessity of R/2 value. Even without this resistor the output will be +5V (no output current in R), why specifically, R/2??
 

when Vin=5V then due to virtual ground the other input's voltage is also 5V and hence no current flows and hence the output voltage is 5V.

as for the R/2... it is to make the input impedance of both the inputs equal.... those two R in the other input can be considered as voltage dividers and hence their impedance is R/2.

Regards
Anand
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…