# Input Dynamic range of Op-Amp circuits

#### testing12

Joined Jan 30, 2011
80
Hello Everyone,

Im looking for some help with calculating the input dynamic range of the op-Amp circuit below. Can someone please direct me?

I know that if V1(t) falls outside the input dynamic range, the circuit saturates, ie goes to either +/- 13 volts..Just not sure how to find the range.

Thank you.

#### testing12

Joined Jan 30, 2011
80
Here is ym attempt: for a summing amplifier:

V(out)= - (Rf/R1)*v1 -(Rf/R2)*v2

13 = -(33/10) *(v1) - (33/100) *(2)

v1= +/- 4.14 volts

#### t_n_k

Joined Mar 6, 2009
5,455
You effectively have an inverting / summing amplifier.

Vo(t)=-(K1*Vb(t) + K2*Va(t))

K1 & K2 an be deduced from the resistor values

#### t_n_k

Joined Mar 6, 2009
5,455
Looks like you have the idea.

#### testing12

Joined Jan 30, 2011
80
Thank you sir!!
I wasnt to sure about how the capacitor will affect all this.

#### t_n_k

Joined Mar 6, 2009
5,455
At this point the question is only concerned with the voltage Va(t) and not the source 'Sync-out' . If the level at 'Sync-out' was quoted rather than Va(t) then one would have to consider a more complex analysis. What you have done is correct.