Reference voltage buffer

Abstract

The invention provides a reference voltage buffer. The reference voltage buffer includes a reference voltage generator for generating a reference voltage, a first operational amplifier, a first transistor, a first set of resistors, a first load, a second transistor, a second set of resistors, and a second load. The first operational amplifier receives a reference voltage and a feedback signal and generates a control signal. The first and second transistors are controlled by a control signal. The first set of resistors is coupled to the first transistor and the first load, wherein the feedback signal is generated from internal nodes of the first set of resistors. The second set of resistors is coupled to the second transistor and the second load. The reference voltage generator, the first load, and the second load have the same characteristics in response to a temperature change. According to the invention, a suitable output reference voltage can be provided for a subsequent circuit in a faster stable time.

Description

technical field [0001] The present invention relates generally to reference voltage buffers and, more particularly, to reference voltage buffers with faster settling times and larger full scale. Background technique [0002] An analog-to-digital converter (ADC) usually has a reference voltage buffer to provide multiple reference voltages to a comparator in a quantizer. As advanced semiconductor processes develop and clock signals become faster and faster, voltage reference buffers encounter many design issues such as stability issues, signal quality, and process-voltage-temperature (PVT) Variety. Specifically, when the comparator in the quantizer starts to use the reference voltage to sample the input signal, the reference voltage may drop suddenly, and the reference voltage buffer needs settling time to make the reference voltage return to the original level . As the frequency and sampling rate of the clock signal become faster, the settling time of the reference voltage...

AI Technical Summary

Problems solved by technology

However, larger full-scale designs may result in an unstable reference voltage

Also, if the reference voltage buffer uses an active device as a load to generate the reference voltage, the reference voltage buffer may suffer from PVT problems, the reference voltage becomes unstable, causing problems for the quantizer

Images