FAN2509S26X

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

The FAN2509S26X is a micropower low-dropout (LDO) linear voltage regulator from the FAN2508/09 family, manufactured by onsemi. It provides a fixed output voltage of 2.6V with a maximum load current capability of 50mA. The device utilizes CMOS technology to achieve ultra-low power consumption, featuring a ground pin current of 25µA at full load and less than 1µA in shutdown mode. It operates within an input voltage range of 2.7V to 6.5V and offers a typical dropout voltage of 50mV at 50mA. Pin 4 serves as an open-drain error flag output that indicates when the output voltage drops below 95% of the nominal value due to fault conditions such as thermal overload or input dropout.

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

• Integrated open-drain error flag output on Pin 4 to signal fault conditions like thermal shutdown or insufficient input voltage
• Ultra-low quiescent current consumption with less than 1µA shutdown current for extended battery life
• Exceptional loop stability allowing compatibility with a wide variety of external capacitors without strict ESR requirements
• Onboard thermal protection circuitry that automatically disables the output if junction temperature exceeds safe limits

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

• GSM and TDMA cellular handsets
• Portable computers including laptops and notebooks
• Personal Digital Assistants (PDAs)
• Portable cameras and video recorders

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

Verify the specific ordering suffix '26X' confirms the 2.6V fixed output voltage and tape-and-reel packaging configuration. Ensure the component matches the SOT-23-5 package outline and that the manufacturer designation aligns with the original Fairchild Semiconductor specifications now managed by onsemi. Confirm datasheet revision status for accurate electrical characteristics.

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

Select this component for applications requiring a fixed 2.6V supply rail with minimal footprint. The FAN2509 variant is specifically chosen over the adjustable FAN2508 when system monitoring of output voltage integrity is required via the error flag. Consider the thermal resistance characteristics of the PCB layout, as the device relies on copper area for heat dissipation to maintain operation within the specified junction temperature limits under high load conditions.

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

This part belongs to the FAN2508/FAN2509 family of 50mA CMOS LDO regulators designed for portable electronics. The family distinguishes between adjustable (FAN2508), bypass-capable fixed (FAN2508-XX), and error-flag fixed (FAN2509-XX) versions. The FAN2509S26X represents the fixed-output iteration optimized for noise-sensitive applications where fault detection is necessary, utilizing the same compact SOT-23-5 surface-mount package as its counterparts.

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

The FAN2509S26X is pin-compatible with many popular older BiCMOS designs. Direct substitutes may include other parts from the FAN2508/09 series with different output voltages or functions, provided the pin assignments for VIN, GND, EN, and VOUT remain identical. Verify that any replacement maintains the 50mA current rating and compatible dropout voltage characteristics.