Fixed voltage virtual ground generator for single supply analog systems

US5280235A · kind A · utility

Assignee

• TEXAS INSTRUMENTS INCORPORATED · US

Inventors

• Todd M. Neale · Carrollton, US
• Brad Whitney · Oakland, US
• Mark E. Granahan · Allentown, US

Key dates

• Filing date: Mar 24, 1992
• Grant date: Jan 18, 1994
• Expiry date: Mar 24, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S323/907
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A method and apparatus for a circuit physically realizing a virtual ground function and having improved accuracy and stability is described. A stable bias current source is coupled to a bandgap reference generator and resistances to produce a virtual ground voltage of a precise value, this voltage is then coupled to an operational amplifier configured in a unity gain configuration. The circuit thus created offers numerous advantages over the virtual ground circuits in use in the prior art. An integrated circuit implementing this circuit is described, and alternative packaging embodiments are disclosed. Other embodiments are also disclosed.