Low thermal hysteresis bandgap voltage reference
US7772920B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2009 |
| Grant date | Aug 10, 2010 |
| Priority date | — |
| Expiry date | May 29, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/30
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A first and a second group of individual transistors in a voltage reference may collectively function as a first and a second composite transistor with a first and a second emitter area equal to the combined areas of the emitters of the first and the second groups of individual transistors, respectively. The second emitter area may be larger than the first emitter area. The stability of the reference voltage may depend upon the stability of the ratio between the first emitter area and the second emitter area. The first group of individual transistors may not be at the center of an arrangement of the second group of individual transistors. The constant reference voltage may vary due to thermal hysteresis by less than 200 parts per million over a 40 degree centigrade temperature range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.