Patent · US Expired

Level shifter apparatus and method for minimizing duty cycle distortion

US7245172B2 · kind B2 · utility

6Cited by
11References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 8, 2005
Grant dateJul 17, 2007
Priority date
Expiry dateJan 20, 2026

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K19/018521
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A level shifter apparatus and method for minimizing duty cycle distortion are provided. The level shifter includes a bank of comparators each having an associated threshold built into it. The comparators compare a difference in source voltages for two power domains to these built-in thresholds and output a signal indicative of whether the threshold is exceeded. The output signals from the comparators are provided to a thermometric decoder which generates control signals based on these output signals. The control signals are used to control stages in a level shifter for modifying the voltage output of the level shifter. Individual stages may be enabled to thereby monotonically modify the voltage output of the level shifter and thereby decrease a time required to achieve a voltage having a level that causes a state change in a driven circuit. As a result, duty cycle distortion is minimized and maximum operational frequency is increased.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.