Solutions for HW3
Divija Gogineni
September 25, 2019
1. A peak detector is shown on page 27 of note set set2.pdf. Assuming ideal diodes with
VD,ON = 0, determine the steady-state value of the output if the input is switched between
±A, for C2= 2C1, and C2=C1/2.
For C2= 2C1: The following terms contribute to VOUT (k)
•Charge sharing from C1to C2:C1A
C1+C2
=A
3
•Contribution from input voltage: C1A
C1+C2
=A
3
–Contribution from VOUT (k−1):C2VOU T (k−1)
C1+C2
=2
3VOU T (k−1)
Thus VOUT (k) = A
3+A
3+C2VOU T (k−1)
C1+C2
–Since VOU T (0) = 0, we have VOUT (k→ ∞) = 2A
3+2A
3.2
3+2A
3.(2
3)2+· · · = 2A
•Similar proof for C2=1
2C1for which
VOU T (k) = 2A
3+2A
3+1
3VOU T (k−1)
1
