Implementation of GaAs E/D HEMT analog components for oversampling analog/digital conversion

The paper presents design considerations and implementation of analog components, including an operational amplifier, latched comparator, 1 bit D/A converter and second-order modulator, for a fully differential delta-sigma modulation oversampling A/D converter in a 0.5 /spl mu/m GaAs E/D HEMT technology. On-wafer measurements demonstrate that the second-order modulator achieves a 60 dB dynamic range at a Nyquist conversion rate of 5.0 MHz with a sampling frequency of 500 MHz.