Title:
Engineering Specification: 12.1-inch AMLCD Monitor
Page
11 of 27
Document Number
: 023-0284-00
Revision:
A
4.2 Signal Functions
4.2.1 Video Parameters
As seen by the source, input resistance is 75-ohm, ±10%; input capacitance at (150 MHZ)
<10-pF.
Coaxial cable is provided for video signal line(s) to match impedances and for EMI
attenuation. The video input signal will have a range of 0-mv to 714-mv (maximum) where
0-mv is minimum luminance. Rise and fall times for the input signal (10% - 90%) will be
#
5-ns (Figure 6).
When terminated with a 75-ohm termination, the dark state (black level) is defined as a
level between 0-mv and 10-mv. The white state (full white) is dependent on the VGA
controller driving the Monitor. Maximum levels may range from 550-mv to 714-mv.
Nominal 680-mv input voltage shall be defined as the default for supplier setup
requirements.
Displayed image intensity and colors will change linearly with the video analog input.
This is necessary to provide a uniform user color change on the screen in response to a
uniformly stepped analog input. The Monitor must be capable of resolving a minimum
color range of 262,144 displayable colors (6 bit resolution for Red, Green and Blue). This
interpolates to 64 shades of gray (or color) at the Red, Green, and Blue analog video
inputs. Accomplishing specified shades of gray requires a “Video Gain” control
adjustment (Section 15.0 ) of Red, Green, and Blue analog input signals based on the
maximum output level range previously specified.
RISE
TIME
FALL
TIME
NEG
POS
HIGH
STEADY
LEVEL
LOW
STEADY
LEVEL
OVERSHOOT
Figure 5. Rise / Fall Time
