A Two-Step Multi-Stage Noise-Shaping Incremental Analog-to-Digital Converter (Invited Paper)

High resolution wide bandwidth applications require power-efficient high-accuracy data converters. Multi-Stage Noise-Shaping (MASH) is a useful technique for the design of stable high-order ΔΣ modulators. In this paper, we propose a two-step MASH incremental ADC (IADC). In the first step it performs a third-order coarse quantization. Re-using the same hardware, in the second step the circuit performs fine quantization as a second-order IADC. Thus, it achieves fifth-order noise shaping with only three amplifiers. For a low oversampling ratio OSR = 32, the signal-to-noise ratio can be boosted by about 30 dB. The scheme is suitable for wide bandwidth applications.