Phase interpolator and a delay circuit for the phase interpolator

US8446198B2 · kind B2 · utility

Assignee

• TEXAS INSTRUMENTS INCORPORATED · US

Inventors

• Anant Shankar Kamath · Bengaluru, IN
• Krishnaswamy Nagaraj · Emmaus, US
• Sudheer K. Vemulapalli · Allen, US
• Jayawardan Janardhanan · Bengaluru, IN
• Karthik Subburaj · Bengaluru, IN
• Sujoy Chakravarty · Bengaluru, IN
• Vikas Sinha · Austin, US

Key dates

• Filing date: Apr 16, 2010
• Grant date: May 21, 2013
• Expiry date: Jan 14, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03H11/265
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

Phase interpolator and a delay circuit for the phase interpolator. The phase interpolator includes a variable delay circuit to rotate phase of an input clock to generate a phase rotated signal. The phase interpolator also includes a delay locked loop coupled to the variable delay circuit to generate a plurality of phase shifted outputs. The delay locked loop includes a plurality of delay elements. Each delay element includes a multiplexer and a delay cell coupled to the multiplexer. The multiplexer is configurable using a first control signal to output one of the phase rotated signal and a phase shifted output of the plurality of phase shifted outputs. The delay cell delays one of the phase rotated signal and the phase shifted output to generate another phase shifted output of the plurality of phase shifted outputs.