Sigma-delta modulator

US7250886B1 · kind B1 · utility

Assignee

• DIALOG SEMICONDUCTOR INC. · DE

Inventors

• Dirk Killat · Kirchheim unter Teck, DE
• Andreas Adler · Neckargemünd, DE

Key dates

• Filing date: Mar 20, 2006
• Grant date: Jul 31, 2007
• Expiry date: Mar 20, 2026

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03M3/464
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

Circuits and methods to achieve a low-noise and low offset continuous sigma-delta modulator used e.g. for battery management are disclosed. Continuous integration of input is enabled by special switching principle of three parallel integrators. Precharging of integrator output in so called pre-run mode minimizes integrator leakage and non-ideal effects by connecting a Gm in pre-run mode either to input voltage or to a reference voltage depending this Gm is being used in a following clock period. Parasitic effects due to switching at first integration capacitor are minimized by using buffer amplifiers tracking the voltage on integration capacitors.