Differential amplifier circuit with rectifier for optical pick-up device
US7514665B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2006 |
| Grant date | Apr 7, 2009 |
| Priority date | — |
| Expiry date | Nov 22, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A light-receiving amplifier circuit in which diodes are commonly connected to a differential amplifier circuit including a transistor of a differential input stage that is an inverting input unit, and are connected between photodiodes (PDs) biased in a forward direction with respect to a direction of photocurrent, and current supply switch transistors. Current supply switch transistors are each connected in parallel between a differential input transistor and a corresponding PD. When light enters into a first PD, a corresponding transistor is turned ON, while a non-corresponding transistor is turned OFF. A non-corresponding diode becomes biased in a backward direction, so that a photocurrent generated due to the light having entered into a second PD is prevented from flowing into the differential amplifier circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.