UCC3837D

Overview

The UCC3837D is an 8-pin N-FET linear regulator controller designed for extremely low dropout applications using an external N-channel MOSFET. It operates from input voltages as low as 3V and provides high current levels suitable for custom processor voltages, bus termination, and logic level supplies below 3V. The device features a built-in charge pump to drive the external MOSFET gate, ensuring optimal efficiency. Key electrical parameters include a 1.5V reference voltage, a supply current of 1.5mA at 5V VDD, and a minimum start voltage of 2.00V. It supports output voltages down to 1.5V and includes duty ratio mode overcurrent protection.

Feature Summary

• Integrates an on-board charge pump to generate gate drive voltage for external N-MOSFETs, enabling extremely low dropout performance.
• Features duty ratio mode overcurrent protection that limits average power dissipation during fault conditions while maintaining peak transient loading capability.
• Allows flexible design optimization with adjustable output voltages starting from 1.5V and programmable current limit settings.

Applications

• Custom processor voltage regulation
• Bus termination voltage generation
• Logic level voltage supplies below 3V

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm RoHS compliance status and check for lifetime buy announcements, as indicated in packaging data. Ensure proper handling for moisture sensitivity level 2 components. Validate package markings against official datasheet specifications to prevent counterfeit risks.

Selection Notes

Select this controller when designing linear regulators requiring minimal dropout voltage and high efficiency with external pass transistors. Consider the internal charge pump limitations and ensure adequate capacitor sizing on the CAP pin for stable gate drive. Evaluate thermal management requirements for the external MOSFET under fault conditions due to the duty-cycled protection mechanism.

Part Context

The UCC3837D belongs to the UCC3837 family of linear regulator controllers manufactured by Texas Instruments. It shares functional similarities with the UCC1837 and UCC2837 variants, differing primarily in operating temperature ranges. The D suffix indicates an SOIC-8 surface-mount package. This component serves as a versatile solution for creating efficient linear power stages where standard three-terminal regulators are insufficient.

Replacement Considerations

UCC2837D is a verified substitute within the same family offering extended industrial temperature range capabilities.