LM1229VEC National Semiconductor, LM1229VEC Datasheet - Page 10

• Manufacturer Part Number: LM1229VEC
• Description: I2C Compatible CMOS TV RGB and Deflection Processor
• Manufacturer: National Semiconductor

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Pin
No.
23
54
Application Information
PIN CONNECTIONS
1
2
3
4
5
6
7
8
9
VDRIVE
VDRIVE
V
Pin Name
REF
VEHT1
VEHT2
C
C
OSC
ALC
Caps
OUT
REF
Schematic
10
C
constant vertical ramp amplitude according to the
value set in the vertical height register.
C
slope of the vertical ramp.
These two outputs provide the inputs to a
vertical output amplifier which drives the vertical
yoke winding. Since the VDRIVE
from 1.5V to 2.5V peak to peak, the gain of the
output amplifier must be set with external
resistors to match the vertical yoke being used.
The VDRIVE
voltage with time).
Provides filtering for the internal voltages which
set the internal bias currents in conjunction with
R
be 10 µF, pin 23 should be 54 µF and pin 54
should be .01 µF. These capacitors should be
placed as close to their pins as possible.
This input pin is used to control the height of the
vertical ramp based on changes in the high
voltage. A 1V negative change at pin 8 causes a
maximum of 5% reduction in the ramp amplitude
when the VEHT[3:0] is set to 0xF. If this pin is
not used, bit 3 of the SYNCPOL register should
be set to 1. The values shown give a 350 mV
change at pin 8 from a 2.5V change at the ABL
pin.
This input pin is used to control the level of the
E-W parabola based on changes in the high
voltage. A 1V negative change at pin 9 causes a
maximum of 300 mV increase in the ramp DC
level when the VEHT[7:4] is set to 0xF. If this pin
is unused, bit 4 of the SYNCPOL register should
be set to 1. The values shown give a 350 mV
change at pin 9 from a 2.5V change at the ABL
pin.
ALC
OSC
EXT
. For proper filtering, pins 5, 6 and 7 should
is the feedback loop filter which maintains
is the capacitor which determines the
OUT
slope is positive (increasing
Description
OUT
amplitude is