High bandwidth video output amplifier circuit for high resolution cathode ray tube image displays
US5661436A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1996 |
| Grant date | Aug 26, 1997 |
| Priority date | — |
| Expiry date | Apr 19, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/68
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A high bandwidth video output amplifier circuit suitable for driving a cathode ray tube for printing high resolution images on photographic stock with good tonal reproduction includes a high voltage amplifier comprising an emitter follower amplifier with a constant current collector load circuit inputing to an emitter follower buffer current amplifier circuit which drives an output load device such as a cathode ray tube. The constant current collector load provides desired high amplifier gain. A negative feedback path is coupled from the buffer output to the input of the high voltage emitter follower amplifier circuit via an intermediate emitter follower buffer at the input to the voltage amplifier transistor. The feedback provides stable, controlled overall voltage gain and the intermediate buffer amplifier isolates the video input and feedback path from the collector-base Miller capacitance of the voltage amplifier transistor thereby providing a significant extension of the amplifier bandwidth. The voltage amplifier transistors are mechanically mounted on a common dual heat sink to enhance dc operating stability of the overall circuit. The constant current circuit is provided wit…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.