Sierra Video 10 Series - Manual (Page 15)

SIERRA VIDEO
9
Video Modules
Introduction
Sierra Video makes a complete line of high performance 10 output video distribution
amplifiers for broadcast, production, and presentation applications.
Each of the frames in the Series 10 DAs use 10 output plug-in modules. Modules can be
loaded into frames can be different types. Frames only supply power and I/O
connections.
501011 Basic Video DA
The 501011 Basic Video DA is the SVS low noise, low distortion, 150 MHz bandwidth
1x10 plug-in DA module.
Circuit Description
The 501011 is a plug-in module. Refer to the 501011 schematic diagrams in the
schematic section of this manual.
The 501011 is powered by low voltage AC which comes into the module through the
edge connector. When dual supplies are ordered, the two supplies enter the 501011
separately and are paralleled after the AC to DC rectification. This provides total in-frame
isolation between the two supplies. U5 provides regulated +5VDC and U4 provides
regulated -5VDC. On the front edge of the 501011 separate LEDs indicate the presence
of the + and – 5 VDC levels.
Input video enters on the edge connector pin 2. The incoming signal’s shield enters on
pin 1 and is then connected directly to the circuit ground.
The 501011 employs a two stage gain process. First a current feedback op amp provides
the variable gain via the trim pot in its feedback loop. The gain is set by trim pot R28
located on the front of the 501011.
Next, there are two more of the same op amps each feeding the 75 Ohm source
terminated signals.
Chapter 3