FAN1587AT33

Special Purpose Regulators Overview

The FAN1587AT33 is a fixed-output low dropout linear regulator manufactured by Fairchild Semiconductor, now part of onsemi. It provides a stable 3.3 V output with a maximum continuous current capability of 3 A. The device operates within an input voltage range of 2.4 V to 12 V and features a typical dropout voltage of 1.3 V at full load. Designed for high-efficiency power management, it includes internal current limiting and thermal shutdown protection. The component is housed in a TO-220-3 package, suitable for through-hole mounting, and supports operation temperatures from 0°C to +125°C.

Special Purpose Regulators Feature Summary

• Provides a fixed 3.3 V regulated output with 3 A current capacity
• Optimized for low voltage applications requiring fast transient response
• Includes internal short-circuit current limit and thermal overload protection

Special Purpose Regulators Applications

• Power supply for Intel Pentium processors
• GTL+ bus termination voltage regulation
• General-purpose low dropout regulation in embedded systems

Special Purpose Regulators Procurement Notes

Verify the manufacturer origin carefully, as Fairchild Semiconductor was acquired by onsemi. Confirm the specific suffix 'AT33' matches the required TO-220-3 package and fixed 3.3 V output. Check for RoHS compliance status and lead times, as availability may vary between legacy Fairchild stock and current onsemi production runs. Ensure the datasheet version corresponds to the specific manufacturing era.

Special Purpose Regulators Selection Notes

Select this component when a robust, high-current LDO is needed for processor core or I/O voltage rails. The TO-220-3 package offers superior thermal dissipation compared to surface-mount alternatives like DPAK. Consider the input voltage range; ensure the source voltage remains above 4.6 V (3.3 V + 1.3 V dropout) under all load conditions. Verify that the thermal resistance of the PCB layout can handle the power dissipation at maximum load.

Special Purpose Regulators Part Context

The FAN1587 series belongs to a family of high-performance low dropout regulators designed primarily for powering complex digital logic families. Originally developed by Fairchild Semiconductor, these parts were widely used in PC architecture during the Pentium era. The series includes adjustable and fixed voltage variants, with the AT33 specifically targeting the 3.3 V standard required by later generation microprocessors and memory modules.

Special Purpose Regulators Replacement Considerations

Public confirmed substitute part numbers: RC1587AT33, FAN1587AMC33X.