FAN2503S27X

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

The FAN2503S27X is a fixed-output low-dropout (LDO) voltage regulator from the FAN2502/03 family, manufactured by onsemi. It provides a regulated 2.7 V output with a maximum continuous current of 150 mA. The device utilizes CMOS technology and features an SOT-23-5 surface-mount package. Key electrical parameters include a dropout voltage of 150 mV at full load, a ground pin current of 25 µA, and an input voltage range of 2.7 V to 6.5 V. It incorporates thermal limiting protection and an enable/shutdown control function.

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

• Integrated error flag output on Pin 4 that indicates when the output voltage drops below 95% of the nominal value due to fault conditions such as input dropout or overheating.
• Enable/Shutdown control allows the user to disable the regulator output to conserve power, reducing supply current to less than 1 µA.
• Onboard thermal protection circuitry shuts down the output if the die temperature exceeds 150°C, re-enabling automatically once cooled.
• Optimized for loop stability across a wide range of external capacitor ESR values, accommodating various ceramic and tantalum types.

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

• Cellular phones and accessories
• Portable cameras and video recorders
• Laptop, notebook, and palmtop computers

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

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm the specific suffix 'X' corresponds to the Tape & Reel packaging format containing 3000 units per reel. Ensure the part number matches the exact 2.7 V fixed output variant with the Error flag function on Pin 4. Check for any obsolescence notices or lifecycle status updates from onsemi prior to finalizing procurement plans.

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

Select this component for battery-powered portable applications requiring low quiescent current and high efficiency under light loads. The fixed 2.7 V output is suitable for powering digital logic or RF circuits in GSM/TDMA handsets. Consider the SOT-23-5 package size for space-constrained designs. Verify that the required output current does not exceed 150 mA and that the input voltage remains within the specified 2.7 V to 6.5 V range for proper regulation.

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

The FAN2503S27X belongs to the FAN2502/FAN2503 micropower LDO family designed for cost-effective performance in portable devices. Unlike the adjustable FAN2502, the FAN2503 series fixes the output voltage via internal feedback. The 'S27' designation specifies the 2.7 V output level, while the 'X' suffix denotes tape-and-reel packaging. This family replaces older BiCMOS designs with more efficient CMOS technology.

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

FAN2503S27X_NL

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

What is the function of Pin 4 on the FAN2503S27X?

Pin 4 serves as an open-drain Error Flag (ERR) output. It goes LOW when the output voltage drops below 95% of the nominal rated voltage due to faults like input dropout, overheating, or overloading.

How does the Enable pin operate?

Applying a voltage of 0.4 V or less to the Enable pin disables the output, reducing quiescent current to less than 1 µA. A voltage of 2.0 V or greater enables the device. Floating this pin may cause erratic operation.

What is the thermal shutdown behavior?

If the junction temperature exceeds 150°C, onboard thermal protection disables the output. The device remains shut down until the temperature drops below this limit, at which point it automatically re-enables.