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:
Nov. 09, 1999
Filed:
Aug. 13, 1997
Michael G Tuthill, Limerick, IE;
Analog Devices, Inc., Norwood, MA (US);
Abstract
A switched current temperature sensor circuit with compounded .DELTA.V.sub.BE includes an amplifier having an inverting input with a corresponding non-inverting output, and a non-inverting input with a corresponding inverting output; a first PN junction connected to the non-inverting input through a first input capacitor and a second PN junction connected to the inverting input through a second input capacitor; a current supply including a low current source and a high current source; a switching device for applying in the auto zero mode the high current source to a first terminal of the first PN junction and the low current source to a first terminal of the second PN junction for providing the V.sub.BE1 of the first junction to the first capacitor and for providing the V.sub.BE2 of the second junction to the second capacitor and for applying in the temperature measurement mode the low current source to the first terminal of the first PN junction and the high current source to the first terminal of the second PN junction for providing the negative .DELTA.V.sub.BE1 of the first PN junction to the first capacitor and the positive .DELTA.V.sub.BE2 of the second PN junction to the second capacitor. The first feedback capacitor interconnected between the inverting output and non-inverting input and a second feedback capacitor interconnected between the non-inverting output and inverting input in the amplifier to define the gain on each of the .DELTA.V.sub.BE inputs to produce a differential voltage across the outputs representative of the average temperature of the PN junctions; and first and second reset switching devices for discharging the first and second feedback capacitors, respectively, and for enabling the amplifier to equalize its input in the auto-zero mode.