SSH and SHHGaInP/GaAs HBT divide-by-3 prescalers with true 50% duty cycle

Abstract

Two 50% duty cycle divide-by-3 prescalers - sample-sample-hold (SSH) and sample-hold-hold (SHH) prescalers - in the 2 pm GaInP/GaAs heterojunction bipolar transistor (HBT) technology are realised. Current switchable emitter couple logic D flip-flops are employed to form both prescalers. The proposed SHH prescaler functions up to 2.6 GHz while the SSH prescaler operates from DC to 1.75 GHz. The maximum operating frequency of the SHH prescaler is enhanced about 50% compared with that of the SSH prescaler owing to better signal synchronisation.