Slew Rate

Thread Starter

ac_dc_1

Joined Jan 27, 2013
74
I have the following problem:


Consider that the product between the gain-bandwith of an OpAmp is 1Mhz.Design a circuit that has a 34dB with a bandithw of 50 khz..

I have no idea how to solve this.The gain in dB is given by \(20*log(Vout)/(Vin)=34dB\)...How can i determine Vin with the data given?
\(

w*Vomax=SR

2*pi*fomax*vomax=SR

fomax=SR/(2*pi*vomax)

\)
Question 2)If an OpAmp has a diferential gain Ad=10^4 and a comon gain Ac=10^-1 and a error of about 10% when the output tension is 2.5V

Determine Vc and Vd in the input (Comon voltage and diferential voltage)

So i know that \( Vo=Ad(Vp-Vn)-Ac((Vp-Vn)/2)\)

I believe i need another equation in order two find the two variables Vc and Vd

The info that the error is 10% when Vin=2.5 V does that tell me that Vp-Vn=0.10


Question 3)Consider an OpAmp with SR=4V/micro second

Calculate the maximum frequency that a 5v sinusoide may have in order to be amplified without SR distortion

*\(

w*vomáx=SR
2pi*f*5=4*10^6

f=127,3385 kHZ

f<=127,3385 kHZ
\)

is that it?
Thanks


Question 4) If we increase the resistor in a integrator circuit what happens(the resistor of RC constant)

I believe that the frequency of integration increases..And what else?


Question 5) What happens if we increase the resistor R(not the feedback resistor the other) in a hysteresis comparator that is whose output is conected to the capacitor of a integrating circuit?It increseases the integrating period?

Thanks
 
Last edited:

thatoneguy

Joined Feb 19, 2009
6,359
I have the following problem:


Consider that the product between the gain-bandwith of an OpAmp is 1Mhz.Design a circuit that has a 34dB with a bandithw of 50 khz..

I have no idea how to solve this.The gain in dB is given by 20*log(Vout)/(Vin)=34dB...How can i determine Vin with the data given?
\(
34dB= 20 \cdot log \frac{V_out}{V_in}
\)

Re-arranging:

\(
V_out = V_in \cdot 10^{\frac{34}{20}}
\)
Assuming V_in = 1V

\(
V_out = 50.11872V
\)

Therefore, the Voltage gain is about 50.12.

Checking our work...
\(
dB=20 \cdot log(\frac{50.11872}{1})
dB = 34dB
\)

The rest of your post is simply math, though you left units out, and did not format it very well, making it difficult to understand quickly.
 

Thread Starter

ac_dc_1

Joined Jan 27, 2013
74
\(
34dB= 20 \cdot log \frac{V_out}{V_in}
\)

Re-arranging:

\(
V_out = V_in \cdot 10^{\frac{34}{20}}
\)
Assuming V_in = 1V

\(
V_out = 50.11872V
\)

Therefore, the Voltage gain is about 50.12.

Checking our work...
\(
dB=20 \cdot log(\frac{50.11872}{1})
dB = 34dB
\)

The rest of your post is simply math, though you left units out, and did not format it very well, making it difficult to understand quickly.

Ok what about question 2 and 3?Any ideas??

Thanks
 
Last edited:
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