Buffer with inductance-based capacitive-load reduction

Abstract

A buffer circuit uses (e.g., active) inductors for driving capacitive loads. In one embodiment, the buffer circuit has one or more stages, each stage having one CMOS inverter. Each CMOS inverter has one NMOS transistor and one PMOS transistor and is coupled to a stage input and a stage output. Additionally, at least one stage of the buffer circuit has two inductors, each coupled between a different voltage reference for the buffer circuit and the stage output. One inductor has a PMOS transistor coupled to the gate of an NMOS transistor and the other inductor has an NMOS transistor coupled to the gate of a PMOS transistor. When driving capacitive loads, the inductors partially tune out the apparent load capacitance C, thereby improving the charging capabilities of inverter and enabling quicker charge and discharge times. Furthermore, partially tuning out apparent load capacitance facilitates the driving of larger capacitive loads.