Low-power LVDS driver using InP HBT ECL circuits for SKA

Indium phosphide Heterojunction Bipolar Transistors (HBTs)-based, low power, Low Voltage Differential Signalling (LVDS) driver to interface digital circuits operating at varied logic levels is designed using Emitter Coupled Logic (ECL) circuits operating at 2 GHz clock speed. The core of the ECL circuit is based on a voltage to current converter/buffer. The total power dissipation of the driver with LVDS compatible output levels is less than 15mW. This is achieved with a relaxed geometry of 5 ∼μm² area HBT devices fabricated on Molecular Beam Epitaxy (MBE) grown wafers. The circuit makes use of dynamic switching of output transistors without using any complex circuitry, which reduces total power consumption without appreciably compromising on speed or area. These results are better than those reported on 0.35 μm CMOS technology and is comparable with designs built on 0.35 μm BICMOS technology.