Enhanced transconductance amplifier
US4593252A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 3, 1984 |
| Grant date | Jun 3, 1986 |
| Priority date | — |
| Expiry date | May 3, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2200/261
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An amplifier having a very high gain-bandwidth product includes a first operational amplifier having its positive input connected to the amplifier's input. The output of the first operational amplifier is connected to the base of a transistor, the emitter of which is coupled by a gain-setting resistor to ground and is also directly connected to the negative input of the first operational amplifier. The collector of the transistor is connected by a resistive load to a supply voltage and is also directly connected to the negative input of a second operational amplifier. The output of the second operational amplifier is coupled by a capacitor back to its negative input. The output of the second operational amplifier is coupled by a feedback resistor back to the emitter of the transistor. The output of the second operational amplifier is connected to the output terminal of the amplifier. The effective dynamic emitter resistance of the transistor is reduced by the gain of the first operational amplifier causing the transconductance of the amplifier to be proportional to the open or closed loop gain thereof for all practical values of closed loop gain. In a described embodiment of the in…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.