Temperature sensor to run from power supply, 0.9 to 12 volts
US6137341A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1998 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Sep 3, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/222
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A temperature sensor circuit generates an output voltage that is linearly proportional to temperature over a desired temperature range with a desired offset voltage. The temperature sensor includes two Proportional To Absolute Temperature (PTAT) current sources that generate PTAT currents and two transistors which conduct the PTAT currents with different current densities to establish a basic voltage PTAT across a resistor. An offset resistor coupled between the bases of the two transistors and a circuit node, shifts the basic PTAT voltage by an offset voltage. A first gain circuit couples to the collector of the first transistor and the offset resistor and generates a servo current (i.e., a current that tends to move the circuit to the desired state by correcting an error) to servo the base of the first transistor when there is a difference between the first transistor's collector current and the PTAT current. A second gain circuit generates a second servo current to servo the emitter of the second transistor when there is a difference between the second transistor's collector current and the PTAT current. These servo currents drive the two transistors such that the second gain ci…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.