LM1267
Pin Descriptions
Pin No.
18
19
20
Pin Name
(Continued)
Schematic
Description
Video outputs of the LM1267. The ideal
driver for this part is the LM246X CRT driver
family, which has the necessary gain of 26
dB or 20 V/V.
Blue Video Out
Green Video Out
Red Video Out
21
V
Ref
Out
A 0.1 µF capacitor must be placed close to
this pin for decoupling the internal V
Ref
. This
pin may be used for an external voltage
reference with proper buffering.
22
ABL
The Auto Beam Limit control reduces the
gain of the video amplifier in response to a
control voltage proportional to the CRT beam
current. The ABL acts identically on all three
channels. ABL is required for CRT life and
X-ray protection.
23
Clamp Pulse
This input accepts a standard TTL or CMOS
input. The signal can be either positive or
negative going. The polarity is set in register
0Bh bit-3. The signal activates the clamp
pulse for DC restoration of the video input.
The AC coupling capacitors at the video
inputs are used for holding the DC correction
voltage, eliminating the need for additional
capacitors.
H flyback is an analog signal input from the
monitor horizontal scan. The LM1267 is able
to generate an accurate blanking pulse in
the video outputs from this input. The
horizontal flyback from the monitor must be
a clean signal, with no ringing or other noise
on the signal.
24
H Flyback
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