What combination most determines the speed of recovery in a peak detector?

What combination most determines the speed of recovery in a peak detector?

• A. The diode speed, the op-amp bandwidth, and the hold capacitor size.
• B. Only the diode speed.
• C. The input impedance of the following stage.
• D. The color of the PCB.

Answer: (A)

Recovery speed in a peak detector comes from how quickly the stored peak on the hold capacitor can be removed when the input drops. In an active peak detector, that discharge path is set by the diode dynamics, the amplifier’s ability to respond, and how much charge is stored. If the diode is slow or has troublesome reverse recovery, the capacitor can’t release charge quickly, delaying the drop in the held peak. The amplifier’s bandwidth controls how fast the feedback loop can react to changes and pull the capacitor voltage toward the new input value; a wide bandwidth means a faster, tighter tracking during the recovery. The size of the hold capacitor directly sets how much charge is stored, so a larger capacitor requires more charge to be discharged, which slows recovery, while a smaller one allows quicker release. So, the fastest and most accurate recovery depends on the combination of diode speed, op-amp bandwidth, and hold-capacitor size. The following stage’s input impedance can influence leakage paths a bit, but it isn’t the primary determinant, and the color of the PCB has no bearing on the electrical behavior.

Recovery speed in a peak detector comes from how quickly the stored peak on the hold capacitor can be removed when the input drops. In an active peak detector, that discharge path is set by the diode dynamics, the amplifier’s ability to respond, and how much charge is stored.

If the diode is slow or has troublesome reverse recovery, the capacitor can’t release charge quickly, delaying the drop in the held peak. The amplifier’s bandwidth controls how fast the feedback loop can react to changes and pull the capacitor voltage toward the new input value; a wide bandwidth means a faster, tighter tracking during the recovery. The size of the hold capacitor directly sets how much charge is stored, so a larger capacitor requires more charge to be discharged, which slows recovery, while a smaller one allows quicker release.

So, the fastest and most accurate recovery depends on the combination of diode speed, op-amp bandwidth, and hold-capacitor size. The following stage’s input impedance can influence leakage paths a bit, but it isn’t the primary determinant, and the color of the PCB has no bearing on the electrical behavior.