LM2450

220V Monolithic Triple Channel 7 MHz DC Coupled CRT

DTV Driver

General Description

The LM2450 is a triple channel high voltage DC coupled

CRT driver circuit designed for use in DTV applications. The

IC contains three high input impedance, wide band amplifi-

ers which directly drive the RGB cathodes of a CRT. Each

amplifier has a summing input where the DC level of the

output is controlled by a low voltage DC input voltage. Nor-

mally the DC input voltage is from a DAC. Each channel has

its gain internally set to −54 and can drive CRT capacitive

loads as well as resistive loads present in other applications,

limited only by the package’s power dissipation.

The IC is packaged in a 15-lead TO-247 molded plastic

power package designed specifically to meet high voltage

spacing requirements. See Thermal Considerations section.

Features

n

7 MHz bandwidth

n

100V black level adjustment range using 0V to 5V input

n

Current output for IK feedback systems

n

Greater than 130V

n

0V to 5V input voltage range

n

Stable with 0 pF–20 pF capacitive loads and inductive

peaking networks

n

Convenient TO-247 staggered thin lead package style

Applications

n

DC coupled DTV applications using the 480p format as

well as standard NTSC and PAL formats.

Connection Diagram

Schematic Diagram

20144301

FIGURE 1. Top View

Order Number LM2450TB

See NS Package Number TB15A

20144302

FIGURE 2. Simplified Schematic Diagram

(One Channel)

December 2005

© 2005 National Semiconductor Corporation

DS201443

www.national.com