Integrated semiconductor circuit for thermal measurements

• US 5,064,296 A
• Filed: 06/22/1990
• Issued: 11/12/1991
• Est. Priority Date: 06/23/1989
• Status: Expired due to Term

• Current Assignee: Bronkhorst High-Tech BV Nijverheidsstraat 1A NL- 7261 AK Ruurlo
• Original Assignee: Bronkhorst High-Tech BV
• Inventors: Huijsing, Johan H., Riedijk, Frank R.
• Primary Examiner(s): Levy, Stuart S.
• Assistant Examiner(s): RHOA, JOSEPH
• Application Number:
  US07/542,177
• Time in Patent Office: 508 Days
• Field of Search: 374/163, 374/128, 374/170, 374/171, 374/172, 374/173, 374/183, 364/557, 73/204.11-204.24, 250/370.15, 375/28, 341/43
• US Class Current: 374/163
• CPC Class Codes: G01F 1/68 by using thermal effects
• CPC Class Codes: G01F 1/696 Circuits therefor, e.g. constant-current flow meters
• CPC Class Codes: G01K 17/04 Calorimeters using compensation methods , i.e. where the absorbed or released quantity of heat to be measured is compensated by a measured quantity of heating or cooling

Abstract

Integrated semiconductor circuit for thermal measurements, comprising at least a thermal signal comparator (8), the comparator (8) being provided with a signal feedback loop containing a DA signal converter (3), more specifically, the comparator (8) being a temperature or a heat current comparator, the DA signal-converter (3) comprising a thermal output and the signal feedback loop comprising components for the transfer of thermal signals.

Claims

1. Integrated semiconductor circuit for measurements of thermal signals, comprising

a thermal signal comparator (8) having a first thermal input, a second thermal input and an electrical digital output;

a feedback loop connected between the output and the first input of the comparator, said feedback loop comprising a digital-analog (DA) signal converter (3) which provides an analog thermal output;

an adder unit for heat currents having an output connected to a heat capacity having a temperature output connected to the first thermal input of said comparator;

said feedback loop comprising a gating unit having a first input connected to the output of the comparator, a second input connected to a clock pulse and a digital electric output connected to the input of the digital-analog (DA) converter.

2. Integrated semiconductor circuit according to claim 1, wherein the adder unit comprises means for adding negative heat currents, and wherein the DA converter comprises a cooling element.