An ultra-high-speed,master-slave voltage comparator circuit is designed and fabricated using InP/GaInAs double heterojunction bipolar transistor technology with a current gain cutoff frequency of 170 GHz. The complete chip die,including bondpads,is 0.75×1.04 mm~2.It consumes 440 mW from a single -4 V power supply,excluding the clock part.77 DHBTs have been used in the monolithic comparator.A full Nyquist test has been performed up to 20 GHz,with the input sensitivity varying from 6 mV at 10 GHz to 16 mV at 20 GHz.To our knowledge,this is the first InP based integrated circuit including more than 70 DHBTs,and it achieves the highest sampling rate found on the mainland of China. An ultra-high-speed, master-slave voltage comparator circuit is designed and fabricated using InP / GaInAs double heterojunction bipolar transistor technology with a current gain cutoff frequency of 170 GHz. The complete chip die, including bondpads, is 0.75 × 1.04 mm ~ 2.It consumes 440 mW from a single -4 V power supply, excluding the clock part. 77 DHBTs have been used in the monolithic comparator. A full Nyquist test has been performed up to 20 GHz, with the input sensitivity varying from 6 mV at 10 GHz to 16 mV at 20 GHz.To our knowledge, this is the first first InP based integrated circuit including more than 70 DHBTs, and it achieves the highest sampling rate found on the mainland of China.