Low-voltage rail-to-rail transconductance amplifier

Abstract

The invention discloses a low-voltage rail-to-rail calculation transconductance amplifier. The transconductance amplifier comprises an input stage and an output stage, wherein the input stage is a mutually complementary master-slave differential amplifier composed of an NMOS differential transconductance stage of a band-tail current source and a PMOS differential transconductance stage of the band-tail current source, and the output stage is a common-source amplifier of a folded structure; the output current of the mutually complementary master-slave differential amplifier is input into the source electrode and the drain electrode of a common-grid tube respectively, then overlaid, and converted into a first voltage, and the first voltage is output; the output signal of a first stage is amplified through the common-source amplifier of the output stage, and the amplified output signal of the first stage is output through the common-source amplifier of the output stage. The minimum working voltage of the low-voltage rail-to-rail transconductance amplifier can be a power voltage of 0.6 V, and that no dead zone of the amplifier exists within a whole common-mode input range can be guaranteed; the voltage of the grid electrode of a tail-current tube can be dynamically adjusted under varying conditions of different input voltages, the common-mode voltage dead zones are significantly reduced, and rail-to-rail input or output can be achieved.

Description

technical field [0001] The invention relates to a low-voltage rail-to-rail operational transconductance amplifier, belonging to the technical field of amplifiers. Background technique [0002] With the continuous reduction of process size and the demand for low power consumption, the power supply voltage of analog integrated circuits is constantly evolving towards a lower direction. Designers began to try to operate the circuit from a supply voltage of 0.6V or lower. However, due to the constraints of the leakage current problem, the threshold voltage of the transistor does not continue to decrease with the feature size but stabilizes at the level of 350mV~450mV, which brings great challenges to the traditional analog circuit design. In analog integrated circuits, the transconductance amplifier is the core module that constitutes most feedback circuits, and its importance is self-evident. [0003] In low-voltage applications, rail-to-rail input / output is required for ampli...

AI Technical Summary

Problems solved by technology

When the power supply voltage is close to the threshold voltage, it is difficult for the traditional differential pair structure to keep the tail current source constant

At the same time, the lower supply voltage also limits the convergence effect of the complementary input stage on common-mode voltage changes

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