Amplifier input circuit
US4780689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1987 |
| Grant date | Oct 25, 1988 |
| Priority date | — |
| Expiry date | Jul 20, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/3076
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved amplifier input circuit for use as the input stage for a current feedback amplifier to reduce offset and limit overload currents. The circuit includes first and second bias current supplies, first and second diodes having anode and cathode terminals, a PNP transistor and a NPN transistor, first and second input terminals, and first and second current sense terminals. Currents flowing through the sense terminals are sensitive to an input current in the first input terminal. Bias currents from the first and second bias current supplies are divided, respectively, between the PNP transistor and first diode, and the NPN transistor and second diode. The base terminals of the transistors are connected in common to the second input terminal. Other embodiments are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.