Bias circuit for controlling bias voltage of differential amplifier
US5488330A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1994 |
| Grant date | Jan 30, 1996 |
| Priority date | — |
| Expiry date | Dec 22, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F2203/45702
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A first differential amplifier includes first and second transistors. A bias circuit includes a second differential amplifier, a constant-current source, and a capacitor. The bases of third and fourth transistors constituting a second differential amplifier, are connected to those of the first and second transistors, respectively. The constant-current source supplies a constant current to the third and fourth transistors, and one end of the capacitor is connected to a connection node of the constant-current source and fourth transistor. In the bias circuit, when a high-level signal is supplied to the base of the first transistor, the capacitor is charged and discharged in accordance with the operations of the third and fourth transistors, with the result that the base potential of the first and second transistors is stabilized, and the operation current flowing through the first differential amplifier is prevented from increasing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.