Chapter 4 Theory of Operation
SCXI-1120/D User Manual 4-2 www.natinst.com
The major components of the SCXI-1120/D are as follows:
• SCXIbus connector
• Digital interface
• Digital control circuitry
• Timing and analog circuitry
The SCXI-1120 consists of eight isolated amplifier channels with gains of
1, 2, 5, 10, 20, 50, 100, 200, 250, 500, 1,000, and 2,000. The SCXI-1120D
consists of eight isolated amplifier channels with gains of 0.5, 1, 2.5, 5 10,
25, 50, 100, 125, 250, 500, and 1,000. The SCXI-1120/D also has a digital
section for automatic control of channel scanning and temperature
selection.
The theory of operation of each of these components is explained in the rest
of this chapter.
Power-Up State
The SCXI-1120/D powers up, or resets, in parallel mode.