LM2465TA/NOPB

Overview

The LM2465TA/NOPB is a monolithic triple high-gain CRT driver designed for color monitor applications. It integrates three high input impedance, wideband amplifiers with an internal gain of -20 to directly drive RGB cathodes. The device operates within a supply voltage range of +60V to +85V and supports bias voltages from +8V to +15V. Electrical characteristics include a typical rise time of 5.5 ns and fall time of 6.0 ns at 40Vpp output swing. It handles capacitive loads up to 20 pF and maintains stability with inductive peaking networks.

Feature Summary

• Integrates three independent high-gain channels with fixed internal gain of -20 for direct CRT cathode driving
• Maintains stable operation with capacitive loads up to 20 pF and inductive peaking networks
• Features industry-standard 9-lead TO-220 staggered lead package for efficient thermal dissipation
• Compatible with LM243X family pinout to facilitate PCB layout reuse

Applications

• Color monitors supporting resolutions up to 1280 x 1024 at 75Hz
• Video display systems utilizing pixel clock frequencies up to 135 MHz
• High-resolution CRT driver circuits requiring video blanking capabilities

Procurement Notes

Verify the component origin as National Semiconductor, now part of Texas Instruments, due to corporate acquisition history. Confirm that the NOPB suffix indicates compliance with RoHS directives. Ensure the specific TA package variant matches the required thermal management needs for the intended application environment.

Selection Notes

Select this component when designing high-bandwidth video paths requiring precise gain matching across multiple channels. The fixed -20 gain configuration simplifies circuit design by eliminating external feedback resistors. Consider the thermal resistance requirements carefully, as power dissipation increases significantly with higher operating frequencies and load capacitance.

Part Context

The LM2465 belongs to the LM243X family of CRT drivers, sharing pinouts with related models like the LM2467, LM2468, and LM2469. This compatibility allows designers to upgrade or replace existing discrete driver solutions without altering the printed circuit board layout. The device targets the 17-inch and low-end 19-inch monitor market segments.

Replacement Considerations

LM2467TA/NOPB

FAQ

How does load capacitance affect the switching speed of the LM2465?

Increased load capacitance degrades the switching speed. Specifically, the rise time increases by approximately 0.12 ns for every 1 pF increase in load capacitance, while the fall time increases by about 0.10 ns per 1 pF.

What arc protection measures are recommended for the LM2465 outputs?

The datasheet recommends using fast transient response clamp diodes (such as FDH400) connected from the cathodes to ground and VCC. Additionally, series resistors and ferrite core inductors should be used to limit arcover current and reduce high-frequency voltage transients.