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. 07, 1978
Filed:
May. 19, 1976
Douglas J Hamilton, Tucson, AZ (US);
University Patents, Inc., Stamford, CT (US);
Abstract
An apparatus for measuring temperature or, alternatively, for measuring the flow of thermal power to a substrate maintained at substantially constant temperature. In accordance with the invention there is provided a semiconductor substrate, such as a silicon substrate. A temperature sensing means is formed in the substrate and is operative to generate a first electrical signal as a function of the temperature of the substrate. Means are provided for generating a reference level, and a comparator is reponsive to the first electrical signal and the reference level for generating a control signal. A heater means is formed in the substrate and means are provided for driving the heater means in response to the control signal. Finally, means are provided for measuring the electrical power input to the heater. The measured electrical power input is, in various applications, a useful indication of the temperature of the ambient environment. In a preferred embodiment of the invention, the temperature sensing means comprises a PN junction in said substrate, and the voltage drop across this junction is used to develop the first electrical signal. In this embodiment, the heater means comprises a transistor formed in the substrate and the control signal is coupled to the base of the transistor. The thermal power flowing from the substrate is determined by the input power to the transistor and this power is, in turn, determined by measuring the collector current of the transistor.