Low skew differential amplifier using tail voltage reference and tail feedback

摘要

Using the tail level referencing for an inverter stage immediately following a differential amplifier provides trip point tracking with the variations in magnitude of the output level swings on the differential amplifier stage output over the operating range of the circuit. When the tail voltage increases and the VOL of the differential stage increases, the trip point of the receiving inverter also increases. When the tail voltage decreases and the VOL of the differential amplifier goes lower, the trip point of the inverter decreases. An additional benefit is provided by the tail connection to the inverter. Faster switching of current from the right side to the left side of the differential amplifier occurs due to the tail node voltage being raised momentarily by a transistor in the inverter stage when the input of the inverter stage transitions high.