SAMPLE-AND-HOLD CIRCUITSCircuit Design
1) For LF 353 op-amp, Input bias current (IB(max)) 200 pA
2) For FET, Gate-source reverse current (IGSS)
3) For FET, Channel resistance (RDS(on))
4) let R1 = R2 = 1 M
5) Capacitor discharge current (Id) = IB(max) + IGSS
6) Compute C1,
7) V = % error due to discharge during the holding time
8) Holding time (th) = t2
9) Compute the acquisition time (t1)
For 0.1% error due to acquisition time,
t1(min) = 7C1RD(on)
10) For FET, Gate–Source Cutoff Voltage (VGS(off))
V1(-) = -VGS(off)
V1(+) Vo