A double-sampling pseudo-two-path bandpass ΔΣ modulator

Abstract

A double-sampling pseudo-two-path bandpass modulator is proposed. This modulator has an output rate equal to twice the clock rate, uses 2 operational amplifiers (op-amps) for an th-order noise transfer function, and has reduced clock feedthrough in the signal path band. The required clocks can be simpler to implement than the conventional pseudo-two-path techniques. The measured signal-to-noise ratio and dynamic range of the fourth-order double-sampling pseudo-two-path bandpass modulator in a 30-kHz bandwidth at a center frequency of 2.5 MHz (at a clock frequency of 5 MHz) are 62 and 68 dB, respectively.