Resolution-enhanced sturdy MASH delta–sigma modulator for wideband low-voltage applications

A resolution-enhanced sturdy multi-stage noise shaping (MASH) delta-sigma modulator is presented. By employing the Leslie-Singh architecture in the first stage and an appropriate second stage digital filtering, the proposed structure could achieve much higher resolution [>80 dB signal-to-quantisation noise ratio] when compared with a traditional sturdy MASH, at a lower oversampling ratio (e.g. 8X). Interestingly, the mismatch between digital and analogue transfer functions is inherently shaped so that the structure is not sensitive to opamp finite gain error. Both these properties make the proposed structure suitable for wideband low-voltage applications. Behavioural simulations are presented to demonstrate the effectiveness of the proposed structure when compared with the prior art of its high performance delta-sigma counterparts.