Trade-Offs in Design of Wide-Band Inverter-Based Amplifiers

Trade-offs in the design of wideband and energy-efficient inverter-based amplifiers (IAs) will be analyzed and compared to the conventional Current-Mode Logic (CML) based circuits. For a proper comparison, the minimum current consumption of generic IA and the CML amplifiers, with and without active-peaking, will be calculated for a set of target Gain-Bandwidth Product (GBWP) values. This study shows that IAs consume not only lower energy and power compared to their CML counterparts for a given speed specification, but also offer a higher maximum achievable operating frequency. Closed-form expressions, with less than 5% mismatch with simulation results, will be provided to analyze speed-power trade-offs in this type of circuit. This study shows that the consumption of IA circuits (with active peaking) can be lowered by a factor of close to two compared to the CML (with active peaking) in CMOS 28 nm technology, while extending the maximum achievable GBWP by about 12%.