Switched capacitor bandgap reference circuit having a time multiplexed bipolar transistor
US5059820A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1990 |
| Grant date | Oct 22, 1991 |
| Priority date | — |
| Expiry date | Sep 19, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/30
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Time multiplexing two or more current sources to source current to a single bipolar transistor achieves a more stable Vbe input for a switched capacitor bandgap reference circuit. With the proper selection of switched capacitor sizes and current sources values to establish a Vbe voltage at the input of a differential amplifier, an output reference voltage can be achieved that is substantially independent of processing and temperature variations as well as circuit aging characteristics. The invention reduces, and in some cases, eliminates the need for trimming values of capacitance or resistance to achieve the desired output reference voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.