Reference voltage generator, having a double slope temperature characteristic, for a voltage regulator of an automotive alternator

US5703476A · kind A · utility

Assignee

• SGS-Thomson Microelectronics S.A. · IT

Inventors

• Mauro Merlo · Pavia, IT
• Franco Cocetta · Cornaredo, IT
• Fabio Marchio · Bareggio, IT
• Massimo Grasso · Pavia, IT
• Bruno Murari · Monza, IT

Key dates

• Filing date: Jul 1, 1996
• Grant date: Dec 30, 1997
• Expiry date: Jul 1, 2016

Classification

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

Abstract

A reference voltage generator having a dual slope temperature characteristic, for use in an automotive alternator voltage regulator, comprises a bandgap circuit (R1,R2,R3,R4) which generates a voltage (A) having a thermal drift coefficient of zero and a voltage (B) having a non-zero thermal drift coefficient. These voltages are applied to a voltage divider (R5,R6) and a voltage-follower type of circuit (OPA1). A unidirectional conduction amplifier circuit (OPA2) has an input terminal connected to an intermediate point (C) on the voltage divider. A second voltage divider (R7,R8) is connected between the output terminals of the voltage-follower circuit (D) and the amplifier circuit (E) . An intermediate node (F) of the second voltage divider is coupled to an output terminal (VREF) of the generator.