BCD analog memory with differential integrated clock pulse generator

Abstract

THE ADVENT of charge transfer devices is expected to make feasible the realization of various signal processing systems such as TV ghost cancellers, VTR jitter cancellers and TV-phone systems. The performance of these devices, however, is severely limited by: 1) the poor signal to noise ratio in a picture tube due to higher harmonic interference from external clock pulse circuits, 2) the output gain and level fluctuation’ ,2 caused by unbalanced clock pulses with ringing and crosstalk varying the effective clock pulse frequency, and 3) narrow dynamic range resulting from the nonlinear gate capacitance. The second limitation arises because the input and output signal charges in a sensing diffusion layer are determined by electrode potential; that is, the clock pulse waveform. A 64 stage bulk charge-transfer device analog memory with a novel clock pulse generator has been developed to eliminate these problems.