Transconductance amplifier circuit
US5357210A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1993 |
| Grant date | Oct 18, 1994 |
| Priority date | — |
| Expiry date | Jul 7, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F1/347
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A transconductance amplifier circuit employs the known combination of a transconductance amplifier and a current comparator (with or without a ratio extender, preferably in the form of a two-stage current transformer) to compare the output current from the transconductance amplifier with that flowing through a reference resistor, both these currents having been derived from the same alternating input voltage. A current corresponding to the unbalanced ampere-turns in the current comparator is used to produce a feed-forward error signal that is used to modify the output of the transconductance amplifier. The invention is characterized by an output transformer that has coaxial inner and outer toroidal magnetic cores, and primary and correction windings outside the outer core. This primary winding receives the output current from the transconductance amplifier and the correction winding receives the error signal. A winding located between the cores detects the error current in the output transformer (its magnetizing current), and injects this error current into the current comparator. The secondary of the output transformer can be a single turn conductor extending through the hole form…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.