Design of Peak Detectors : C1
If the acceptable holding voltage error is 1%, then the maximum capacitor discharge voltage is calculated as 1% of the peak voltage.
For a capacitor discharge voltage V, discharge current Id,
and holding time th, the capacitor (C1) is calculated as
Once the capacitor value has been determined, its maximum charging current should be calculated to arrive at the required maximum output current Io(max) from op-amp A1.
For a peak voltage Vp and minimum signal rise time tr
The frequency response of the operational amplifiers must be high enough to handle the maximum signal frequency.
When a pulse-type input waveform is applied, the op-amp slew rate must be faster than the maximum rate of change of input signals.
A slew rate is three time faster than the rate of change of the signal .
So, for peak signal voltage Vp and rise time tr,