SOLUTION: Hello, We got this basic op amp at TAFE. Vin- db- Vout I know how to work out db and finding Vout but I can't work out how to get Vin. The problem we got is Vin- 26db- 1V Wh

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Hello, We got this basic op amp at TAFE. Vin- db- Vout I know how to work out db and finding Vout but I can't work out how to get Vin. The problem we got is Vin- 26db- 1V Wh      Log On


   

Question 708185: Hello,
We got this basic op amp at TAFE.
Vin- db- Vout
I know how to work out db and finding Vout but I can't work out how to get Vin.
The problem we got is Vin- 26db- 1V What is the formula for working out Vin.
I know Vout is:
Vout= db%2AVin%2F+log20
is there a formula like that to find Vin?
Thank you
PS THe answer given was 50mv but I'm not sure how they worked it out.

Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
10%5E1.301=20 <---> log%2820%29=1.301 so
Solving V%5Bout%5D=db%2AV%5Bin%5D%2F1.301 for V%5Bin%5D we get
highlight%28V%5Bin%5D=1.301%2AV%5Bout%5D%2Fdb%29

V%5Bin%5D=1.301%2A%281Volt%29%2F26=0.050Volt
Converting Volts to milliVolts requires multiplying times 1000:
0.050Volt%2A%281000mVolt%2F1Volt%29=50mVolt