Circuit for determining the output power of switched-mode power supply

US6222748A · kind A · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Hans Niederreiter · Markt Indersdorf, DE
• Peter Preller · Hersbruck, DE

Key dates

• Filing date: Mar 16, 2000
• Grant date: Apr 24, 2001
• Expiry date: Mar 16, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R22/00
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A circuit arrangement is provided that is suitable for determining the output power of switched-mode power supplies. A charge capacitor is charged with a constant current for the duration of the discharging time of a transformer. The voltage across the charge capacitor is integrated by a downstream integration element. The output voltage of the integration element is proportional to the mean power of the switched-mode power supply. The inventive circuit arrangement takes into consideration that the charging and discharging times of the transformer can be different for different switching frequencies of the switched-mode power supply, even when the power output of the switched-mode power supply is the same.