Voltage-Controlled Pulsed Current Source with Hyperbolic, Squared Hyperbolic, and Quasi Dirac Delta Function Time Dependence

Abstract

A voltage-controlled pulsed current source (VCPCS) capable of generating current pulses with four different waveforms in time domain is presented in this paper. These waveforms are the following: hyperbolic waveform in time domain (HWTD), squared hyperbolic waveform in time domain (SHWTD), quasi Dirac delta function (QDDF) based on the HWTD, and QDDF based on the SHWTD. The QDDF is treated as a generalized function (GF) whose limit value leads to the required shape. The controllability of the shapes and frequency of the current pulses is provided by adjustment of the parameters of saw-tooth and triangle control voltages. The design of the proposed VCPCS can be implemented in a standard CMOS technology. However, it has been prototyped here first using discrete off-the-shelf components mounted on a printed circuit board with a single supply voltage of 3.3 V. Measured results confirm the predictions of the analysis performed. Specifically, the measured ratio of the largest and the smallest HWTD current is 7.6 times larger than that in the state-of-the art, for the same supply voltage, which is of particular importance in optical quantum random number generators (OQRNGs).