# Differential Amplifier Design Question

#### jegues

Joined Sep 13, 2010
732
Hello all,

I've been working on the following question (See figure attached).

I'm on part (ii) and the solution gives this circuit (See other figure attached) as the one that will provide a gain of +2V/V.

I'm tried doing some analysis on the circuit to figure out whether this is right or not but I can't conclude that it indeed gives a gain of 2V/V.

What am I doing wrong?

I've got a feeling my calculation for $V_{+}$ is wrong.

Can someone clarify?

#### Attachments

• 97.4 KB Views: 19
• 294.6 KB Views: 13

#### Jony130

Joined Feb 17, 2009
4,931
In your diagram, V+ = Vin
So the gain is equal Av = 1+ R/R = 2V/V