A 2-Bit 4GS/s Flash A/D Converter in 0.18μm CMOS for an IR-UWB Communication System

摘要

A 4GS/s 2-bit non-time-interleaved flash ADC is designed for an IR-UWB (Impulse Radio Ultra Wide Band) receiver. In this flash ADC,implementing differential low-swing operation in analog part and CML (current mode logic) in digital part result in high-speed and low power consumption. Furthermore,because of the low-bit-sampling characteristic of the IR-UWB system,non-time-interleaved structure is used without digital calibration which largely saves the power consumption,chip area and cost. And a differential resistive reference ladder is designed to minimize the inaccuracy of the reference voltage. The proposed ADC dissipates 34mW power from a 1.8V supply while operating at 4GHz. This chip has been fabricated in 0.18 μm 1P6M CMOS process and the ADC achieves 1.86-bit effective number of bits (ENOB) for input signal of lGHz at 4GS/s in simulation of FFT analysis.