"2.97 What is the highest frequency of a triangle wave of 20- V
peak-to-peak amplitude that can be reproduced by an op amp
whose slew rate is 10 V/us (us-microseconds)? For a sine wave of the same frequency, what is the maximum amplitude of output signal that
remains undistorted?"
My answer:
I assume that Sedra is considering a wave without DC component (he does not give any info about this...), so if the wave is alternating between the x axis with 10 V at maximum peak and -10 V at minimum peak it will give a slope of
slope = 20/ T
Well, slope = SR hence 20/T = 10^7 ( since SR = 10 V/us) hence T=2microseconds...
f=1/T == f = 1/2 us ==> f = 500 kHz (Sedra gave the 250 kHz as the final answer?? Maybe he considered 20 V as a peak voltage and not peak-to-peak??)
Then
for the sine wave, considering the frequency 500 kHz it gave
v=vo sin (2*pi* 5*10^5 * t) [V]
dv/dt = v0 * 2*pi*10^5 cos (......) -- but cos (..) is at maximum with 1.. so
dv/dt| (max) = v0 * 2* pi*10^5
SR= dv/dt == 20 *10^6 = v0 * 2*pi*5*10^5 ==
v0 = 3,18 V , (Sedra gave 6,37 V - DOUBLE the mine value)
Please see if I'm right there. Thanks!
peak-to-peak amplitude that can be reproduced by an op amp
whose slew rate is 10 V/us (us-microseconds)? For a sine wave of the same frequency, what is the maximum amplitude of output signal that
remains undistorted?"
My answer:
I assume that Sedra is considering a wave without DC component (he does not give any info about this...), so if the wave is alternating between the x axis with 10 V at maximum peak and -10 V at minimum peak it will give a slope of
slope = 20/ T
Well, slope = SR hence 20/T = 10^7 ( since SR = 10 V/us) hence T=2microseconds...
f=1/T == f = 1/2 us ==> f = 500 kHz (Sedra gave the 250 kHz as the final answer?? Maybe he considered 20 V as a peak voltage and not peak-to-peak??)
Then
for the sine wave, considering the frequency 500 kHz it gave
v=vo sin (2*pi* 5*10^5 * t) [V]
dv/dt = v0 * 2*pi*10^5 cos (......) -- but cos (..) is at maximum with 1.. so
dv/dt| (max) = v0 * 2* pi*10^5
SR= dv/dt == 20 *10^6 = v0 * 2*pi*5*10^5 ==
v0 = 3,18 V , (Sedra gave 6,37 V - DOUBLE the mine value)
Please see if I'm right there. Thanks!
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