A CMOS 0.8-/spl mu/m transistor-only 1.63-MHz switched-current bandpass /spl Sigma//spl Delta/ modulator for AM signal A/D conversion

A 2.5MHz 55dB Switched-Current BandPass Σ∆ Modulator for AM Signal Conversion

We present a Switched-Current (SI) fourth-order bandpass Σ∆ modulator IC prototype. It uses fully-differential circuits in 0.8μm CMOS technology to obtain a Dynamic Range (DR) larger than 55 dB at 2.5MHz center frequency with 30kHz bandwidth in accordance to the requirements of AM digital receivers. The prototype incorporates a single-ended to fullydifferential current-mode buffer for testing p...

A Switched-Current Bandpass Delta-Sigma Modulator

An eighth-order switched-current bandpass delta-sigma modulator is described. Simulations indicate that our 1.2pm CMOS implementation will achieve a S N R of 90dB in the band 10 MHzk150 KHz when clocked at 40 MHz. The modulator makes use of a switched-current resonator based on the N-path technique and the resonator employs regulated-cascode current-copiers to simultaneously achieve high speed ...

A 2.8-V Multibit Complex Bandpass Delta-Sigma-AD Modulator in 0.18µm CMOS

Low-voltage low-sensitivity switched-capacitor bandpass Sigma-Delta modulator

The recent explosion of interest in wireless personal communication systems motivates the development of fully integrated radio receivers. The parallel reduction of the dimension in CMOS technology, and hence higher levels of integration enables the combined integration of bandpass or baseband analog-to-digital converter along with the traditional front-end receiver building blocks. While this ...

A 50-MHz Multibit Sigma–Delta Modulator for 12-b 2-MHz A/D Conversion

Oversampling techniques offer several advantages for the implementation of high-resolution analog-to-digital (A/D) converters in VLSI technologies. This paper examines the application of oversampling techniques to A/D conversion at rates exceeding 1 MHz. A cascaded multibit sigma-delta (2A) modulator that substantially reduces the oversampling ratio required for 12-b conversion while avoiding s...