Programmable Fully Differential Gain Bootstrap Transconductance Amplifier

Abstract

The present invention provides a programmable full differential gain bootstrap transconductance amplifier, comprising: a pre-amplification circuit, which amplifies the differential input signal, and outputs the pre-amplified differential input signal; a rear sleeve type gain bootstrap amplifier circuit, Amplify the output signal of the pre-amplifier circuit to form a differential output signal; the bandwidth programming circuit is used to adjust the bandwidth of the pre-amplifier circuit and the rear-stage telescopic gain bootstrap amplifier circuit according to the programming control signal input from the outside The bandwidth of the output common mode feedback circuit is used to input the common mode feedback signal to the rear-stage sleeve gain bootstrap amplifier circuit according to the differential output signal, so that the rear-stage sleeve gain bootstrap amplifier outputs the common mode level Differential output signals within a predetermined range; the amplification factor of the front pre-amplification circuit is smaller than the amplification factor of the rear-stage telescopic gain bootstrap amplifier circuit. The invention can realize bandwidth increase and has the function of programming and regulating the bandwidth size.

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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