Calibration of a dual-path pulse width modulation system

US10404248B2 · kind B2 · utility

Assignee

• CIRRUS LOGIC, INC. · US

Inventors

• Tejasvi Das · Austin, US
• Alan Mark Morton · Fullerton, US
• Xin Zhao · Austin, US
• Lei Zhu · Beijing, CN
• Xiaofan Fei · Austin, US
• Johann G. Gaboriau · Austin, US
• John L. Melanson · Austin, US
• Amar Vellanki · Cedar Park, US

Key dates

• Filing date: Dec 13, 2018
• Grant date: Sep 3, 2019
• Expiry date: Dec 13, 2038

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02M1/0012
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

A system may include a digital pulse width modulator subsystem, a first path coupled to an output of the digital pulse width modulator subsystem and configured to drive an open-loop driver stage, a second path coupled to the output of the digital pulse width modulator subsystem and configured to drive a closed-loop analog pulse width modulator, a controller to select between the first path and the second path for processing a signal based on one or more characteristics of the signal, and a calibration subsystem configured to calibrate at least one of a first gain of the first path and a second gain of the second path in order that the first gain and the second gain are at least approximately equal at the time of switching selection between the first path and the second path or vice versa, in order to minimize artifacts due to the switching.