FAN1581MX

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The FAN1581MX is a linear voltage regulator IC from onsemi, packaged in a TO-263-5 (DPAK) surface-mount configuration. It provides a positive fixed output of 2.5V with a maximum current capability of 5A. The device operates with an input voltage range up to 7V and features a typical dropout voltage of 0.4V at full load. Quiescent current is specified at 6 mA, with power supply rejection ratio reaching 80 dB at 120 Hz. Protection mechanisms include over-current and over-temperature limiting. The component supports an operating temperature range from 0°C to 125°C.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Ultra-low dropout linear regulation optimized for low-voltage microprocessor applications
• Integrated thermal limiting and over-current protection for system reliability
• Fast transient response and high load regulation accuracy

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• GTL+ bus VTT termination supplies
• Low voltage logic family power distribution
• Embedded processor core voltage regulation
• DDR memory termination supply circuits

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the specific suffix designation carefully, as the base FAN1581 series includes adjustable variants alongside fixed outputs. Confirm that the TO-263-5 package matches the target PCB footprint requirements. Check manufacturer documentation for any recent lifecycle status changes or obsolescence notices, as availability may vary across distributors. Ensure thermal management solutions align with the 125°C junction temperature limit under expected load conditions.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this component when a stable 2.5V rail is required for logic or processor segments within a system powered by a slightly higher voltage source. The low dropout characteristic allows operation closer to the output voltage than standard regulators, reducing power dissipation. Consider the 5A current rating against peak transient loads to ensure adequate thermal headroom. Evaluate the TO-263-5 package size constraints relative to available board space and heat sinking capabilities.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

This part belongs to the FAN1581 family of ultra-low dropout linear regulators originally developed by Fairchild Semiconductor and now managed by onsemi. The series includes various fixed voltage options such as 1.2V and 1.5V versions tailored for specific bus terminations like GTL and CPU buses. The MX suffix specifically denotes the TO-263-5 plastic package variant, distinguishing it from other form factors like TO-252 or TO-220 available within the same functional family.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

Direct substitutes include the FAN1581D25X for a TO-252-5 package equivalent or the generic FAN1581-2.5 for identical electrical performance in different packages. Verify pinout compatibility and thermal resistance characteristics when swapping between package types to maintain system reliability.