Clamp circuit
US6737905B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2003 |
| Grant date | May 18, 2004 |
| Priority date | — |
| Expiry date | Feb 26, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/242
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The clamp circuit clamps an input voltage at prescribed higher and lower clamp voltages which are stabilized under a temperature fluctuation. Transistors Q12 and Q14 are switched on in their linear region. In a lower voltage clamp circuit 18, an Vin detecting circuit 20 outputs Va1 by level-shifting Vin by Q13 and voltage-divides by series resistance circuit 23 the level-shifted Vin, while a reference voltage generating circuit 21 outputs Vr1 by level-shifting 0 V by Q15 and voltage-divides by series resistance circuit 25 the level-shifted voltage. Q11 is switched on, when a comparator 22 determines that Va1 descends and goes across Vr1. Here, Q12 is of the same characteristics as Q14, while Q13is of the same characteristics as Q15. Further, the resistance of the circuits 23 is the same as that of the circuit 25. The higher voltage clamp circuit 19 is similar to the circuit 18.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.