Voltage regulator with clamp circuit
US6208123A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1999 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Jan 26, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/565
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Current drawn from a power supply at the start-up of a voltage regulator is reduced by providing a clamp circuit to clamp the input voltage of an output transistor in the voltage regulator for a predetermined period of time after start-up. The voltage regulator preferably comprises an error amplifier for producing an error signal depending upon the difference between a divided portion of the regulated output voltage and a reference voltage, the error signal for controlling the output transistor to regulate the output voltage thereof, and the clamp circuit includes a charge storage device connected to a current source, and a switch circuit having a first terminal connected to a first voltage sufficient to place the output transistor in a high-resistance state, a second terminal connected to the error signal and the input of the output transistor, and a third terminal connected to the charge storage device for controlling an ON/OFF state of the switch circuit. When the voltage regulator is started, the voltage at the input of the output transistor is clamped to a voltage sufficient to maintain the output transistor in a high-resistance state for a predetermined period of time until t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.