A 20 GS/sec Analog-to-Digital Sigma-Delta Modulator in SiGe HBT Technology

This paper presents a monolithic continuous-time 2
^nd
-order analog-to-digital sigma-delta modulator implemented in third-generation, 200 GHz SiGe HBT technology. The modulator can operate at a sampling rate of 20 GS/sec with SNRs of 30.5 dB over a signal band from DC to 312.5 MHz, and 51 dB over 1 MHz bandwidth. Operating off a +3.5 V power supply, the modulator dissipates a total of 490 mW. The die occupies an area of 1.58 times 1.7 mm
²