Mono-rate and multi-rate hybrid continuous-time ΣΔ modulators with SC feedback DAC

Methods for avoiding the slew-rate limit and the optimal design of hybrid Continuous-Time (CT) ΣΔ modulators with switched-capacitor (SC) DAC are discussed. Limitations on performance due to finite bandwidth and slew-rate of the operational amplifier are analyzed. The use of multi-rate scheme made by a set of time-interleaved SC-DAC moderates the non-linear error caused by the limited slew-rate in mono-rate converter at equal slew-rate. Behavioral level simulations confirm the validity of proposed technique.