The exponential-hold circuit, properties and applications

The authors describe the basic theoretical properties of the exponential-hold circuit. The complete set of calculations for amplitude, phase and group delay is given, together with the normalized graphic representation of the results and further evaluations concerning the harmonics distribution and the selection of the time constant of the exponential hold. This enables a comparison between the already published types of hold-circuits and the exponential hold. Since the exponential hold consists mainly of a voltage source, a resistor and a hold capacitor, the practical realization is similar or easier than the polygonal hold used as an example. Combined with a digital/analog converter and a reconstruction filter, the exponential hold has a large field of application in electronic circuits. The main application range of the exponential hold will be the decoding process from the digital to the analog signal representation