A 12.5-bit 4 MHz 13.8 mW MASH ΔΣ Modulator With Multirated VCO-Based ADC.

A novel MASH delta-sigma (ΔΣ) ADC architecture is introduced that has a multirated voltage controlled oscillator (VCO)-based ADC in its second stage. The architecture allows for low power and high speed operation and is insensitive to the VCO linearity. A prototype consists of a first-order switched-capacitor (SC) modulator operating at 100 MHz in the first stage followed by a second-stage VCO-bas...