LM2415T National Semiconductor, LM2415T Datasheet - Page 6

• Manufacturer Part Number: LM2415T
• Description: IC DRIVER MONOLITHIC TO-220-11
• Manufacturer: National Semiconductor

Specifications of LM2415T

• Display Type: CRT
• Current - Supply: 13mA
• Voltage - Supply: 60 V ~ 85 V
• Operating Temperature: -20°C ~ 100°C
• Mounting Type: Through Hole
• Package / Case: TO-220-11 (Bent and Staggered Leads)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Interface: -
• Configuration: -
• Digits Or Characters: -
• Other names: *LM2415T

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Application Hints
NSC Demonstration Board
Figure 11 shows routing and component placement on the
NSC LM1279/240X demonstration board. The schematic of
the board is shown in Figure 10 . This board provides a good
example of a layout that can be used as a guide for future
layouts. Note the location of the following components:
The routing of the LM2415 outputs to the CRT is very critical
to achieving optimum performance. Figure 12 shows the
routing and component placement from pin 1 of the LM2415
• C55 — V
• C43, C44 — V
• C53–C55 — V
and ground pins
10 and ground
V
CC
clamp diodes. Very important for arc protection.
CC
bypass capacitor, located very close to pin 6
BB
CC
bypass capacitors, located close to pin
bypass capacitors, near LM2415 and
(Continued)
6
to the blue cathode. Note that the components are placed so
that they almost line up from the output pin of the LM2415 to
the blue cathode pin of the CRT connector. This is done to
minimize the length of the video path between these two
components. Note also that D14, D15, R29 and D13 are
placed to minimize the size of the video nodes that they are
attached to. This minimizes parasitic capacitance in the
video path and also enhances the effectiveness of the pro-
tection diodes. The anode of protection diode D14 is con-
nected directly to a section of the the ground plane that has
a short and direct path to the LM2415 ground pins. The cath-
ode of D15 is connected to V
pacitor C55 (see Figure 12 ) which is connected to the same
section of the ground plane as D14. The diode placement
and routing is very important for minimizing the voltage
stress on the LM2415 during an arc over event. Lastly, notice
that S3 is placed very close to the blue cathode and is tied
directly to CRT ground.
CC
very close to decoupling ca-