The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 1982
Filed:
Feb. 18, 1981
Klaus Streit, Tubingen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
The current flowing through a reference resistor constitutes the temperature independent output voltage. This current consists of the sum of a first and second current. The first current is a current which is proportional to absolute temperature and has an amplitude which depends on the value of the first resistor. The second current is proportional to the base-emitter voltage of a transistor and its amplitude depends on the value of the second resistor. The values of the first and second resistor are fixed so that the temperature coefficient of the current flowing through the reference resistor is zero. Specifically, one end of the reference resistor is connected to one side of the operating voltage source while the other side is connected through a series circuit including the emitter-collector circuit of the first transistor and the first resistor to ground potential. A second circuit is connected in parallel with the first circuit. The second circuit consists of the emitter-collector circuit of a second transistor and the second resistor. A semiconductor voltage divider has a first and second tap connected to the base of the first and second transistor, respectively. A constant current is supplied to the voltage divider, either by a constant current source or by a circuit mirroring the current flow through the reference resistor. The values of the first and second resistor are fixed so that the temperature coefficient of the current flowing through the reference resistor is zero.