Programmable fully-differential gain-bootstrap operational transconductance amplifier

Abstract

The invention provides a programmable fully-differential gain-bootstrap operational transconductance amplifier comprising a front-arranged pre-amplifying circuit, a rear sleeve-type gain-bootstrap amplifying circuit, a bandwidth programming circuit and an output common mode feedback circuit. The front-arranged pre-amplifying circuit is used for amplifying differential input signals and outputting pre-amplified differential input signals; the rear sleeve-type gain-bootstrap amplifying circuit is used for amplifying output signals of the front-arranged pre-amplifying circuit to form differential output signals; the bandwidth programming circuit is used for adjusting the bandwidths of the front-arranged pre-amplifying circuit and rear sleeve-type gain-bootstrap amplifying circuit according to programming control signals input externally; the output common mode feedback circuit is used for inputting common mode feedback signals to the rear sleeve-type gain-bootstrap amplifying circuit according to the differential output signals to allow the rear sleeve-type gain-bootstrap amplifying circuit to output different output signals of common mode levels in a predetermined range; the amplification multiple of the front-arranged pre-amplifying circuit is smaller than that of the rear sleeve-type gain-bootstrap amplifying circuit. The programmable fully-differential gain-bootstrap operational transconductance amplifier is capable of increasing the bandwidths and has the function of programming and adjusting the bandwidths.

Description

technical field [0001] The invention relates to a programmable fully differential transconductance amplifier, in particular to a fully differential gain bootstrap transconductance amplifier with a programmable bandwidth function. Background technique [0002] The transconductance amplifier is a functional module that converts the input differential voltage signal into a current signal, and charges and discharges the capacitive load to realize the input-to-output voltage method. The amplifier is an important constituent unit of the pipeline A / D (analog / digital) converter, and its performance has an important influence on the pipeline A / D converter. With the development of the pipeline A / D converter towards high speed and high precision, the requirements for its internal sub-circuits, especially the gain and bandwidth of the amplifier are getting higher and higher. In the MDAC (multiplicative digital-to-analog converter) of the pipeline A / D converter, multiple internal compar...

AI Technical Summary

Problems solved by technology

Among them, the open-loop gain of the single-stage sleeve / folding amplifier is not large enough to meet the accuracy requirements of the pipeline; while in the two-stage Miller compensation amplifier, a considerable part of the power consumption is used for frequency compensation, and the power consumption efficiency is low; Therefore, a single-stage gain bootstrap amplifier is generally used to achieve high gain

[0004] However, the existing single-stage gain bootstrap amplifier technology has at least the following problems: the bandwidth of the single-stage gain bootstrap amplifier is small, which cannot meet the requirements of the current high-speed analog-to-digital converter structure for the amplifier speed; and the general single-stage gain bootstrap amplifier It only has a fixed bandwidth, and it is difficult to meet different speed and stability requirements for complex application environments and processes, temperature, and power supply deviations; at the same time, the single-stage gain bootstrap amplifier also has problems such as a small input range and large input parasitic capacitance. The disadvantages of deteriorating the performance of data converters; these problems limit the application of CMOS (Complementary Metal Oxide Semiconductor) single-stage gain bootstrap amplifiers in high-speed and high-precision analog-to-digital converters

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