TABLE OF CONTENTS Over the past few years the MOS integrated-circuit technology had found wide usage in industry because of its superior logic density, as compared to that achievable with bipolar technologies. Today, with large-scale integration (LSI), tens of thousands of MOS transistors can be placed on a single chip. With feature sizes in the vicinity of 1 ?m invisioned for VLSI, the packing density will no doubt continue to increase with subsequent decreases in the cost for complex digital/analog MOS integrated circuits.
A property unique to MOS integrated circuits is the ability to store charge on a node for several milliseconds and to sense this stored charge continuously and nondestructively. This storage in MOS integrated circuits comes about naturally and cheaply. This property was first utilized in dynamic random-access memories and dynamic logic (e.g., dynamic shift registers). This charge storage feature was first used in analog signal processing with the development of the bucket-brigade shift register. In this device the analog signal is converted into a series of charge packets, with each packet proportional to sampled values of the input analog signal. These charge packets are then passed serially through a chain of MOS capacitors, with charge being passed from one capacitor to another by a switching operation achieved with externally clocked MOS transistors. The charges on these capacitors can be nondestructively sensed and summed in a weighted fashion to realize a sampled-data (sometimes referred to as sampled analog) transversal or finite impulse response (FIR) filter. The subject of...
