Frequency and/or phase characteristic control circuit having controlled current multiplying ratio
US5115154A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 6, 1991 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Feb 6, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0941
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A frequency and/or phase characteristic control circuit comprising a current multiplier and an operational amplifier, the current multiplier containing a pair of diode junctions and a transistor arrangement for differential amplification, the operation amplifier having a capacitor connected to the out-of-phase input terminal thereof. The multiplying ratio of the current multiplier is varied so as to control the frequency and/or phase characteristic. This makes the circuit conducive to being implemented in an IC (integrated circuit). This circuit is particularly suitable for use as a circuit that switches the servo circuits of a laser disc player and a compact disc player.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.