onsemi FAN2514S25X

Overview

FAN2514S25X from Fairchild Semiconductor is a 2.5 V fixed-output CMOS low-dropout (LDO) voltage regulator in SOT-23-5 package, delivering 200 mA output with 200 mV dropout at full load, 75 µA ground current, and enable/shutdown control-designed for power management in CDMA cellular handsets and portable computing devices.

For engineers reviewing the FAN2514S25X datasheet, pinout, applications, or equivalent options, key selection criteria include its 2.5 V fixed output, BYP pin for noise-sensitive bypass capacitor integration, thermal shutdown at 150°C, ultra-low quiescent current in shutdown (<1 µA), and compatibility with ceramic, tantalum, or aluminum electrolytic output capacitors across wide ESR range (10 mΩ to 10 Ω).

Technical Context

The FAN2514S25X uses a P-channel MOSFET series pass element with ~1 Ω on-resistance, enabling low dropout performance superior to bipolar LDOs. Its error amplifier features low-drift bandgap reference (1.32 V nominal) and high-impedance CMOS input, eliminating bias current error in feedback networks.

Loop stability is maintained across wide ESR ranges via innovative compensation design, supporting stable operation with 1 µF minimum output capacitance. The BYP pin accepts 470 pF–10 nF capacitors to reduce output noise without affecting regulation accuracy.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package with 1.3 mm × 2.9 mm footprint, 1.45 mm height, and EIAJ SC-74A mechanical standard. Thermal resistance θ_JA ≈ 220°C/W on minimum copper; improves to ~130°C/W with 4 in² ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with FAN2514S25X, MCP1700T-2502E/TT offers lower quiescent current but forfeits integrated noise filtering, while TCS2102-2.5 eliminates enable functionality-making FAN2514S25X uniquely suited for CDMA time-phased, noise-sensitive, and power-gated portable applications.

Availability

FAN2514S25X is available at Aetrix Electronics and suitable for cellular handset power management, portable imaging subsystems, laptop peripheral rails, and wireless audio device supply requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production lots.

Supply support for FAN2514S25X includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Fairchild Semiconductor was a U.S.-based analog and power IC manufacturer, acquired by ON Semiconductor in 2016, known for high-performance power management and signal-path solutions.

The FAN2514/15 family was designed specifically for micropower, low-noise, fast-enable LDO applications in battery-powered CDMA/GSM/TDMA handsets and portable computing-emphasizing dropout voltage, ground current, and noise performance over legacy BiCMOS alternatives.

FAQ

What is the maximum input voltage for the FAN2514S25X?

The FAN2514S25X supports an input voltage range of 2.7 V to 6.5 V per its Recommended Operating Conditions. Absolute maximum rating is 7 V, but operation above 6.5 V is not guaranteed and may compromise reliability or parametric performance. For optimal dropout and thermal behavior in 2.5 V output applications, VIN should remain within 2.7–5.5 V in most portable designs.

Does the FAN2514S25X require an external bypass capacitor on the BYP pin?

The FAN2514S25X does not require-but strongly benefits from-a 470 pF to 10 nF capacitor between BYP (Pin 4) and GND in noise-sensitive applications such as camera sensors or audio codecs. Omitting it degrades output noise performance (e.g., from <7 µV/√Hz to >20 µV/√Hz), though regulation accuracy remains unaffected. High-quality ceramic or film capacitors are mandatory due to BYP's high impedance and leakage sensitivity.

Can the FAN2514S25X be used with ceramic output capacitors?

Yes, the FAN2514S25X is explicitly designed for stable operation with ceramic output capacitors, including X7R and Y5V dielectrics. Its loop compensation tolerates ESR values from 10 mΩ to 10 Ω, eliminating the instability issues common in older LDOs. A minimum 1 µF ceramic capacitor is recommended, placed close to V_OUT and GND pins for optimal transient response and noise suppression.

What happens when the FAN2514S25X exceeds its thermal limit?

When the FAN2514S25X junction temperature reaches 150°C, its onboard thermal protection circuit disables the output until the die cools below the hysteresis threshold (~135°C). During shutdown, ground current drops to <1 µA. This cycle repeats autonomously if the thermal fault persists. Users can preemptively disable the device via the EN pin to reduce power dissipation and accelerate cooldown.

Is the FAN2514S25X pin-compatible with other members of the FAN2514/15 family?

Yes, all FAN2514/15 variants-including FAN2514S25X, FAN2514S33X, and FAN2515S25X-share identical SOT-23-5 pinouts and footprints. However, Pin 4 function differs: FAN2514S25X uses BYP, while FAN2515S25X uses ERR. Swapping them without circuit modification will cause functional mismatch-e.g., connecting a BYP capacitor to an ERR pin risks incorrect fault flag behavior.