Fully differential class AB amplifier and amplifying method using single-ended, two-stage amplifier

Abstract

A fully differential amplifier includes a first single-ended current mirror type fully differential amplifier outputting a first output signal by two stage amplifying a difference between a first input signal and a second input signal and a second single-ended current mirror type fully differential amplifier outputting a second output signal by two stage amplifying a difference between the first input signal and the second input signal. A first tail of the first single-ended current mirror type fully differential amplifier and a second tail of the second single-ended current mirror type fully differential amplifier are connected to each other and the first output signal and the second output signal are differential signals.

Description

[0001] This application claims priority from Korean Patent Application No. 2007-0029106 filed with the Korean Intellectual Property Office on March 26, 2007, the disclosure of which is hereby incorporated by reference in its entirety. technical field [0002] The present disclosure relates to a differential amplifier, and more particularly, to a two-stage fully differential operational transconductance amplifier (OTA). Background technique [0003] As the application of CMOS technology continues to gradually shrink and the demand for battery-operated portable electronics increases, many constraints arise in designing very large scale integration (VLSI) devices. Typical constraints are the requirement for low voltage operation and low power consumption. [0004] As the trend of using system-on-chip (SOC) devices accelerates, not only digital circuits but also analog circuits are integrated on a single chip. As a result, analog circuits, which are normally less affected by co...

AI Technical Summary

Problems solved by technology

[0007] Although folded cascode amplifiers can provide high gain, they are not suitable for applications with low operating voltage due to high voltage headroom

In addition, the folded cascode amplifier has a complex bias circuit, which increases the circuit area

[0008] Because the high-gain amplifier is implemented as a multi-stage device, an increase in circuit area is inevitable, which makes frequency compensation difficult

Therefore, due to the necessity of frequency compensation using techniques such as Nested Miller Compensation (NMC) or Multipath NMC (MNMC), problems such as design difficulty and power consumption increase according to the hierarchy arise

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