Startup circuit for bandgap reference circuit
US6191644A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1998 |
| Grant date | Feb 20, 2001 |
| Priority date | — |
| Expiry date | Dec 10, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/30
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A bandgap reference circuit (10) with improved startup circuitry is disclosed. The bandgap reference circuit (10) includes a startup node (NBIAS) that is connected to the gates of n-channel MOS transistors (38n, 39n) in first and second conduction legs of a current mirror. A series of inverters (51, 53, 55) turn on a transistor (50) that is connected between a precharge node (TO) and the startup node (NBIAS) in response to a signal (RID) indicating recent power-up of a power supply voltage (V.sub.dd). A capacitor (60) is also provided, and which is discharged upon power-down. The capacitor (60) is connected to the gate of a p-channel transistor (70) that has its source/drain path connected between the precharge node (TO) and the startup node (NBIAS), and that is turned on upon power-up, even if the power-up signal (RID) is not generated, thus ensuring initiation of the bandgap reference circuit (10).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.