Operational transconductance amplifier with a non-linear current mirror for improved slew rate

US6414552B1 · kind B1 · utility

Assignee

• DIALOG SEMICONDUCTOR INC. · DE

Inventors

• Frank Kronmueller · Neudenau, DE
• Paul Zehnich · Altrip, DE

Key dates

• Filing date: Nov 16, 2001
• Grant date: Jul 2, 2002
• Expiry date: Nov 16, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03F2203/45658
• WIPO field: Basic communication processes
• WIPO sector: Electrical engineering

Abstract

A non-linear current mirror is achieved. The non-linear current mirror is particularly useful in the output stage of an operational transconductance amplifier for improving slew rate and stability while maintaining low bias current. The non-linear current mirror circuit comprises, first, a first MOS transistor has gate and drain are coupled together and further coupled to a first current input. A second MOS transistor has gate coupled to the first MOS transistor gate, and the drain is coupled to a second current input. A third MOS transistor has drain is coupled to the second MOS transistor source, and the gate is coupled to the second MOS transistor drain. A fourth MOS transistor has gate coupled to the third MOS transistor gate. The source is coupled to the first MOS transistor source and the third MOS transistor source. Finally, the drain forms a current output.