Continue to Site

Welcome to EDAboard.com

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.

How to calculate Vo in this inverter?

Status
Not open for further replies.

terry_kchai

Junior Member level 2
Junior Member level 2
Joined
Apr 1, 2007
Messages
21
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,419
Hi,guys
in the picture, if Vdd=5V , Vss=-5V; input Vi=±100mV, Vo=±4.5V;
When connect two resistors like this, also let Vi=±100mV, how to calc Vo now?
Thanks
 

Re: an inverter question

Assuming negative feedback (not clearlx shown in the picture), the overall gain is

G=1/((1/A)+Hr) with A=4.5/0.1=45 and Hr=1/11
thus
G=8.84 and Vout=0.1*8.84=0.884 volts.
 
an inverter question

If the triangle is an opamp with its non-inverting input biased at 0V then the gain is 10R/R= 10.0.

So if the input is +100mV then the output is -1.0V. If the input is -100mV then the output is +1.0V.
 

an inverter question

LvW, How do you get this G formula, can you tell me more detail?
Thanks
 

an inverter question

Hei, you can find the solution in any analog text book. As it is negtive FB, we get
Af=Av/(1+Av*F), Av=45, F=1/11

Regards!
 
Re: an inverter question

terry_kchai said:
LvW, How do you get this G formula, can you tell me more detail?
Thanks

Here is the derivation of the formula:

At the input of A two signals are combined:

Va=Vin*(R2/(R1+R2))+Vout*(R1/(R1+R2)) in your case with R1=R and R2=10R.

If you combine this equation with Vout=A*Va you can eliminate Va and arrive at the formula for G=Vout/Vin. Try it by yourself. Its the classical formula for feedback from the control theory.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top