Amplifier having high common mode rejection
US4479093A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1981 |
| Grant date | Oct 23, 1984 |
| Priority date | — |
| Expiry date | Dec 3, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03F3/45479
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An amplifier (10) is disclosed including circuity for improving the amplifiers performance, particularly the common mode rejection of differential amplifiers, by adding the amplifier input signal to the power supply signals which power the amplifier. Voltage dividers (42, 44) are connected between the amplifier output (16) and each of the two power supply rails (26, 28). Each divider includes resistors (46, 48; 50, 52) selected so that the amplifier output is divided down by a factor equal to the gain of the amplifier. The junction signals (V.sub.J1, V.sub.J2) provided by the two voltage dividers thus each includes a component equal to the input signal. The junction voltages are applied to the amplifier power input terminals (18, 20) by respective transistors (60, 62), each connected in a voltage follower arrangement. One embodiment (FIG. 4) incorporates a servo amplifier (100) for DC offset stabilization. Impedances (104, 106) couple the output of the servo amplifier to the voltage dividers so that no loss in common mode rejection results from servo operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.