LM2438T

Overview

The LM2438T is a monolithic triple CRT driver designed for color monitor applications. It integrates three high input impedance, wide band amplifiers that directly drive RGB cathodes with an internal gain of -14. The device operates on +60V to +85V supply voltages and accepts 0V to 5V inputs. It supports capacitive loads up to 20 pF and inductive peaking networks. Key electrical parameters include a rise time of 13.9 ns and fall time of 14.2 ns. The component utilizes a 9-lead TO-220 molded plastic power package.

Feature Summary

• Integrates three high input impedance, wide band amplifiers for direct RGB cathode driving
• Internally set gain of -14 per channel
• Stable operation with capacitive loads up to 20 pF and inductive peaking networks
• Compatible with standard video preamplifiers such as the LM1279

Applications

• Color monitor applications
• 1024 x 768 displays up to 60 Hz refresh rate
• Systems utilizing pixel clock frequencies up to 60 MHz
• Monitors employing video blanking techniques

Procurement Notes

Verify the manufacturer origin, as the datasheet indicates National Semiconductor design transferred to Texas Instruments. Confirm the specific ordering suffix matches the required package style. Ensure compliance with RoHS standards applicable to the production batch. Validate that the component meets the operating temperature range requirements for the intended environment before finalizing procurement.

Selection Notes

Select this component for high-resolution display designs requiring fast transient response. Ensure adequate heat sinking is provided, as case temperatures must remain below 100°C. Verify that the application circuit includes proper power supply bypassing and arc protection components to prevent damage from CRT arcover events. Consider layout constraints to minimize parasitic capacitance in the video path.

Part Context

The LM2438T belongs to the LM243X family of CRT drivers. It is specifically targeted at the XGA resolution market. The device is housed in a 9-lead TO-220 package. It is designed to work in conjunction with video preamplifiers to form a complete video channel from monitor input to CRT cathode.

Replacement Considerations

Consult the LM243X family datasheets for alternative members. Verify pinout compatibility if substituting with other variants within the series.