Linear Delta Modulator Integrated Circuit with 17-Mbit/s Sampling Rate

Abstract

Delta modulation (DM) is an attractive method of analog-to-digital (A/D) conversion in applications where simple and economical designs must be realized without sacrificing conversion quality. This paper describes a new single-chip, bipolar integrated circuit delta modulator that maintains a high conversion resolution over a wide range of sampling frequencies and ambient conditions. Its high-speed operation (maximum sampling rates greater than 15 Mbit/s) is achieved with lower power requirements than with comparable discrete realizations. Low sensitivities to power supply and ambient temperature variations, achieved with a novel logic design, make this circuit useful in a telephone switching office environment and as a buildlng block for other linear and companded analog-to-PCM converters.