A High Linearity Digitally Controlled Phase Interpolator

Abstract

The invention provides a high-linearity digitally phase interpolator, comprising multiple phase interpolation units which are connected mutually in parallel and receive multi-phase clock signals. Each phase interpolation unit comprises three circuit branches. Each circuit branch receives a clock signal, or a clock signal and its differential signal. Three clock signals comprise one clock signal and two clock signals of which phase different is + / -Psi. The circuit branches receive same phase interpolation currents. The currents are output according to a certain proportion and are synthesized into a total current. The interpolator also comprises a current bias array which comprises a decoder. The decoder receives digitally control codes and converts the codes into control signals. The current bias array is connected with the input ends of the multiple phase interpolation units. Under the control of the control signals, multiple phase interpolation currents corresponding to the multiple phase interpolation units are generated. The interpolator also comprises a load network which is connected with the output ends of the multiple phase interpolation units and adds each way of total current and converts the current into a voltage signal.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a high-linearity numerical control phase interpolator based on harmonic suppression technology. Background technique [0002] Phase Interpolator (Phase Interpolator) technology is widely used in circuits such as phase-locked loops and clock recovery, and changes the phase of the output clock signal according to different control signals. The traditional phase control technology is often based on the delay chain structure composed of delay units, but its power consumption and area are large, and the delay time will change with the fluctuation of process temperature and voltage, so a calibration circuit must be added. The phase interpolation technology naturally has a phase period of 360°, so no additional correction is required. [0003] The phase interpolation technology uses the induction formula of trigonometric functions to add two single-tone sine or ...

AI Technical Summary

Problems solved by technology

Among these harmonics, the even order harmonics can be eliminated by differential technology, but the odd order harmonics will still alias with the useful fundamental frequency signal, seriously deteriorating the linearity of the phase interpolator

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