This paper explores the use of ΣΔ techniques for A/D conversion exceeding 1-MHz signal bandwidth. A cascade modulator architecture is proposed which combines single-bit and multi-bit quantization to obtain more than 12-b Dynamic Range (DR) with an oversampling ratio of only 16,
and with neither calibration nor trimming required. Measurements from a 0.7mm CMOS prototype show 74dB DR in 1.1-MHz signal band at 35.7-MHz clock rate, with a power consumption of 55mW from a 5-V supply.
This work has been supported by the European Union, under ESPRIT Project 8795-AMFIS.
Peer reviewed