LMH6321TSX

Overview

The LMH6321TSX is a high-speed unity gain buffer manufactured by Texas Instruments, designed for applications requiring significant current drive capabilities. It delivers a continuous output current of ±300 mA and features an adjustable current limit that can be set from 10 mA to 300 mA with ±5% accuracy using an external reference voltage. The device operates on supply voltages ranging from 5V to ±15V and maintains stability when driving large capacitive loads. Key performance metrics include a slew rate of 1800 V/µs and a small-signal bandwidth of 110 MHz while driving a 50Ω load.

Feature Summary

• Features an adjustable current limit controlled by an external reference voltage, allowing precise setting of sourcing and sinking currents between 10 mA and 300 mA.
• Provides high-speed signal buffering with a slew rate of 1800 V/µs and a bandwidth of 110 MHz under standard loading conditions.
• Capable of driving large capacitive loads without oscillation, ensuring stable operation in demanding circuit environments.
• Includes thermal shutdown protection and an error flag output to indicate when the device temperature exceeds safe operating limits.

Applications

• Line driver circuits
• Pin driver applications
• Sonar driver systems
• Motor control interfaces

Procurement Notes

Verify the specific package variant (SO PowerPAD or DDPAK) required for your thermal management needs. Confirm that the ordering suffix matches the desired tape-and-reel configuration if applicable. Ensure the design accounts for the exposed pad connection requirements for proper grounding and heat dissipation. Check for any specific handling precautions regarding ESD sensitivity during storage and assembly.

Selection Notes

Select this component when high output current drive is necessary alongside wide bandwidth. Consider the adjustable current limit feature for protecting downstream components or managing power dissipation. Evaluate the thermal resistance characteristics of the chosen package against your system's ambient temperature constraints. Ensure the supply voltage range aligns with your system's power rails.

Part Context

This device belongs to the LMH6321 family of high-speed buffers from Texas Instruments. It is often used to boost the current output of operational amplifiers when placed within their feedback loop or utilized as a standalone buffer stage. The family includes variants available in different packages to suit various space and thermal requirements.

Replacement Considerations

Direct substitutes may include other high-current buffers from Texas Instruments such as the BUF634 series, though pinouts and electrical specifications must be carefully compared. Verify that alternative devices offer comparable slew rates and current drive capabilities. Ensure compatibility with existing PCB layouts and thermal management strategies before implementing a replacement.

FAQ

How is the output current limit adjusted?

The current limit is continuously adjustable from 10 mA to 300 mA by connecting an external resistor to a variable reference voltage source at the CL pin.

Is the LMH6321 stable with capacitive loads?

Yes, the LMH6321 is designed to remain stable and will not oscillate even when driving large capacitive loads.