Protection circuit for high side drivers

• US 5,398,148 A
• Filed: 05/14/1993
• Issued: 03/14/1995
• Est. Priority Date: 05/14/1993
• Status: Expired due to Term

• Current Assignee: Chrysler Group LLC (Stellantis NV)
• Original Assignee: Chrysler Corporation (Stellantis NV)
• Inventors: Perkins, Walter R., Smith, Randy T.
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): Medley, Sally C.
• Application Number:
  US08/061,979
• Time in Patent Office: 669 Days
• Field of Search: 361/18, 361/56, 361/91
• US Class Current: 361/18
• CPC Class Codes: H03K 17/06 Modifications for ensuring a fully conducting state
• CPC Class Codes: H03K 17/0826 in bipolar transistor switches

Abstract

A protection circuit for high side drivers is dependent upon load impedance to operate. The protection circuit includes a plurality of transistors and resistors and also a capacitor. The circuit monitors the voltage drop across the emitter-collector junction of a transistor in order to turn the flow of current to the electronic module on or off.

Claims

1. A protection circuit for high side drivers for use in an internal combustion engine controller module, said protection circuit being connected to a vehicle battery and comprising:

a level shifter circuit which is connected to the controller module for interfacing an input signal from the controller module, said level shifter circuit including a first resistor connected to the controller module and a first transistor having a base connected to said first resistor;

a protector circuit connected to said level shifter circuit and the battery for protecting the controller module from short circuits, said protector circuit includinq a second resistor connected between a collector of said first transistor and the battery, a third resistor connected to the battery, a second transistor having an emitter connected to the battery and a base connected to said third resistor, a third transistor having an emitter connected to the battery and a base connected to a collector of said second transistor, a fourth resistor connected between the base of said third transistor and the collector of said first transistor, a fifth resistor connected to the collector of said first transistor, a fourth transistor having a base connected to said fifth resistor, a capacitor connected to the base of said fourth transistor, and a sixth resistor connected between an emitter of said fourth transistor and the base of said second transistor; and

an output lead connected to a collector of said third transistor and a collector of said fourth transistor of said protector circuit for sending a signal to a predetermined electrical component.