Stabilized voltage regulator circuit, particularly for use with a serially connected PNP transistor

US4176309A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Alfred Schulz · Oberriexingen, DE
• Uwe Kiencke · Ludwigsburg, DE
• Gunther Honig · Markgröningen, DE

Key dates

• Filing date: Mar 27, 1978
• Grant date: Nov 27, 1979
• Expiry date: Mar 27, 1998

Classification

• Technology area (CPC G): Physics
• CPC primary: G05F1/575
• WIPO field: Control
• WIPO sector: Instruments

Abstract

To permit low differences between regulated output voltage and unregulated input voltage, for example in the order of only 200mV, a control loop formed of a serially connected PNP transistor 11, a reference voltage generator 15, a voltage divider 13 connected across the regulated output, and a comparator-amplifier 14 comparing the output taken from the voltage divider 13 and the reference and providing an error control signal has a second control loop connected thereto which includes a transistor and a current sensing resistor connected to the base of the control transistor 11 and a second comparator comparing the actual current flow through the transistor 18 and the error signal to stabilize the control transistor. A switching network 16 can be additionally connected to modify or affect the error signal applied to the second control loop.