Integrator steady state error

Thread Starter

mentaaal

Joined Oct 17, 2005
451
Hey guys,

I am doing a homework problem. We have to calculate the integrator steady state error for an integrator with:

Rin = 10k
Cint = 10nF
Ib = 100nA
Vio = 2mV
Iio = 10nA

The formula for integrator errrors is:

1/RC∫Vio dt + 1/c∫Ib dt + Vio

What i have done is this: (based on a previous example given to us)

1/(10k*10nF)*2mv + 1/10nF*100nA + 2mv

But when i do this my results is like in the tens of volts! because of the first multiplication.....

Your thoughts?
 

mik3

Joined Feb 4, 2008
4,843
By assuming Ib and Vio to be constant the correct expression is that:

1/(10k*10nF)*2mv*t + 1/10nF*100nA*t + 2mv

t=time in seconds

thus the error increases with time as the output does.
 

Thread Starter

mentaaal

Joined Oct 17, 2005
451
Thats what i was thinking but i was taking notes as gospel again and not trusting my own thoughts on it. Cheers mike.
 
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