Bandgap voltage reference using bipolar parasitic transistors and MOSFET's in the current source
US5132556A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 17, 1989 |
| Grant date | Jul 21, 1992 |
| Priority date | — |
| Expiry date | Nov 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/30
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In a CMOS bandgap reference circuit, the respective collectors of two lateral parasitic NPN transistors are connected to the two nodes of a current mirror. The emitter circuit of the first parasitic NPN transistor includes a resistor, whereby the base-emitter junction current densities of the parasitic NPN transistors are maintained at a preselected ratio. A second resistor common to the emitter circuit of both parasitic NPN transistors is provided, whereby .DELTA.V.sub.BE having a positive temperature coefficient and V.sub.BE of the second parasitic NPN transistor having a negative temperature coefficient cancel one another. The temperature independent voltage across the common resistor and the base-emitter junction of the second transistor is buffered by a unity gain amplifier. The output of the unity gain amplifier is used to drive the parasitic NPN transistors and also is furnished as the reference voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.