Two proposed BiCMOS inverters with enhanced performance

Abstract

The BiCMOS technology finds wide applications when driving heavy loads such as those associated with off-chip loads or long runs within the chip. In this paper, two novel BiCMOS inverters that depend on using Darlington BJT pairs are presented. Also, the operation of the two proposed BiCMOS inverters as amplifiers is discussed. We present closed-form analytical expressions for the low-to-high propagation delay, the high-to-low propagation delay, and the inverter-based amplifier parameters such as the gain and bandwidth under arbitrary load capacitance and transistors’ parameters. The operation of these two inverters is verified by simulation using the 45 nm CMOS predictive-technology model (PTM) with a power supply voltage, VDD, equal to 1 V. The proposed inverters show superior performance compared with the CMOS inverter, the conventional R-circuit BiCMOS inverter, and the full-swing CMOS/bipolar inverter when driving heavy loads even at low supply voltages.