Method and apparatus for drain switching with replication loop for fast LED turn on time
US9024677B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 2012 |
| Grant date | May 5, 2015 |
| Priority date | — |
| Expiry date | Jun 27, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/04206
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for current drain switching with a replica loop. The method comprises the steps of: matching a voltage across a current sense resistor with a voltage created by a reference current across a matched reference resistor; replicating an operating point of an output transistor using a scaled matched replica of the output transistor and the current sense resistor. The method then shifts a feedback voltage from the output sense resistor to the matched replica sensor and shifts the output of a gate from an output transistor to the replica transistor. A first switch is then actuated in order to preserve the gate charge of the output transistor. A second switch is actuated to sample and hold a drain voltage in the buffer in order to bias the drain of the replica transistor. A third switch is then activated to stop the output current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.