Low noise quantized feedback configuration

Abstract

The invention provides a low noise quantized feedback configuration. Described herein is an improved apparatus for increasing the performance of a [sigma][delta] modulator, which may function as an ADC. In one embodiment, the [sigma][delta] modulator comprises a voltage to current converter, a capacitor connected between two outputs of the voltage to current converter to receive a differential input current, and a switch that can switch between connecting each output of the voltage to current converter to ground while disconnecting the other output of the voltage to current converter. In thisembodiment, the [sigma][delta] modulator has no common mode control loop, and no reference current. This results in decreased complexity, i.e., fewer components, as well as reduced noise.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to Provisional Application No. 62 / 691,504, filed June 28, 2018, and U.S. Application No. 16 / 454,010, filed June 26, 2019, both of which are incorporated by reference Its entire content is incorporated herein. technical field [0003] The present invention relates generally to sigma delta modulators, and more particularly to sigma delta modulators without a common mode control loop. Background technique [0004] The analog-to-digital conversion can be performed using quantized feedback in the control loop. Analog-to-digital converters (ADCs) with such characteristics are often referred to as sigma delta (ΣΔ) converters or ΣΔ modulators, a modulator term referring to an output digital data stream with a certain pattern of symbols or controlled by a control loop. Modulation applied to it by the road. The terms ΣΔ modulator and noise shaping control loop are often used interchangeably in...

AI Technical Summary

Problems solved by technology

[0008] The common-mode control portion of circuit 100, i.e., the components below transistors M1 and M2, add complexity and cost

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