EL240.128.45 Operations Manual (020-0345-00C)
11
Dimming
The dimming control circuitry on the display allows the user to adjust the
luminance from 5 % to 95 % of the maximum brightness.
To control the display luminance, connect a 50 k
Ω
variable resistor
between ground and the dimming pin (LUMA). The full resistance of 50
k
Ω
will result in 95 % of the maximum luminance. Reducing the
resistance will reduce the luminance, with resistance of 0
Ω
yielding
roughly 5 % of the maximum luminance.
Alternatively an external voltage or current-mode D/A converter may be
used to dim the display by sinking a maximum of 250
µ
A for maximum
dimming from LUMA to ground. When left open, the luminance will remain
at the maximum level.
Table 7. Luminance Control.
Maximum (No resistor connected): 100 % (Default)
Maximum (50 k
Ω
resistor connected): 95 %
Minimum (0
Ω
resistor connected): 5 % maximum
Open Circuit voltage 4 V nominal
Sink Current 250
µ
A max, Vin = 0 V
Luminance values are measured as a percentage of full On Luminance
(with the external resistor disconnected.)
Self-Test Mode
The display incorporates a self-test mode composed of a 1 x 1
checkerboard and full-on pattern displayed at 240 Hz. Upon power up,
the 1 x 1 pattern is displayed for several seconds, then the full-on pattern
is displayed continuously. The self-test mode is entered by leaving the
SELFTEST pin pulled high. For normal operation the SELFTEST pin must
be pulled to a logic low. If the SELFTEST pin is pulled high during normal
operation, the display will enter the self-test mode with the all-pixels-on
pattern.
Power-up Sequence
No special power-up or video sequencing is required.
