onsemi FAN2502S26X

Overview

FAN2502S26X from Fairchild Semiconductor is a 2.6 V fixed-output CMOS low-dropout (LDO) voltage regulator in SOT-23-5 package, delivering 150 mA output current with 150 mV dropout at full load, 25 µA ground current at 150 mA, and enable/shutdown control - designed for power management in space-constrained portable electronics such as cellular handsets and notebook computers.

For engineers reviewing the FAN2502S26X datasheet, pinout, applications, or equivalent options, key selection criteria include fixed 2.6 V output, bypass-capacitor–optimized noise performance, thermal shutdown at 150°C, ultra-low quiescent current, and compatibility with ceramic, tantalum, or aluminum electrolytic output capacitors across wide ESR ranges (10 mΩ to 10 Ω).

Technical Context

The FAN2502S26X employs a P-channel MOSFET series pass element with ~1 Ω on-resistance, enabling low dropout voltage under load. Its CMOS error amplifier features high-impedance input and internal 1.32 V bandgap reference, ensuring stable regulation without external feedback resistors for fixed-voltage variants.

Pin 4 functions as BYP (bypass), accepting a 470 pF capacitor to reduce output noise; it lacks ADJ or ERR functionality. Thermal protection disables output above 150°C junction temperature, and enable logic (VIH ≥ 2.0 V, VIL ≤ 0.4 V) reduces ground current to <1 µA in shutdown mode.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (EIAJ SC-74A), 2.9 mm × 1.6 mm footprint, 1.1 mm max height, with exposed pad not electrically connected. Thermal resistance θ_JA = 220°C/W (minimum PCB copper), θ_JC = 130°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-2602E/TT and TCS2112-2.6V, the FAN2502S26X uniquely balances ultra-low dropout (150 mV), dedicated BYP noise suppression, and enable control in a 150 mA SOT-23-5 package - making it optimal for noise-critical portable applications where input headroom and EMI performance are constrained.

Availability

FAN2502S26X is available at Aetrix Electronics and suitable for cellular handsets, portable cameras, and notebook subsystems requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for FAN2502S26X 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 semiconductor company specializing in power management, analog, and interface ICs before its acquisition by ON Semiconductor in 2016; its legacy LDO portfolio remains widely deployed in portable electronics.

The FAN2502/FAN2503 family was engineered for GSM/TDMA handsets and portable computing devices, emphasizing micropower operation, low dropout, and robust capacitor compatibility to simplify design in battery-powered systems.

FAQ

What is the output voltage tolerance of the FAN2502S26X over temperature and load?

The FAN2502S26X delivers 2.6 V output with ±2% accuracy across –40°C to +125°C junction temperature and 0.1 mA to 150 mA load current, per Electrical Characteristics table (Rev. 1.1.7). This tolerance includes line regulation (0.3%/V) and load regulation (1.0–2.0%) contributions, verified under specified test conditions (VIN = VOUT + 1 V, TA = 25°C).

Can the FAN2502S26X be used without connecting a capacitor to the BYP pin?

Yes, the FAN2502S26X operates fully functional without a BYP capacitor; however, omitting the 470 pF capacitor increases output noise - particularly in the 10 Hz–1 kHz band - where measured noise rises above 7 µV/√Hz. The BYP pin is optional for cost-sensitive or non-noise-critical applications, but recommended for RF, audio, or precision analog circuits powered by FAN2502S26X.

What is the minimum input voltage required for the FAN2502S26X to maintain regulation at 150 mA load?

The FAN2502S26X requires VIN ≥ 2.75 V to sustain 2.6 V output at 150 mA, based on maximum dropout voltage of 180 mV (typical 150 mV) per Electrical Characteristics. At 2.7 V input, regulation fails under full load; design margin should include worst-case dropout (180 mV) plus tolerance stack-up, making 2.75 V the practical minimum for reliable operation.

Does the FAN2502S26X provide reverse current protection?

No, the FAN2502S26X does not integrate reverse current protection. When VIN falls below VOUT, body diode conduction in the internal P-channel MOSFET allows reverse current flow from VOUT to VIN. External solutions - such as a series Schottky diode or ideal diode controller - are required if backfeed prevention is needed in the application using FAN2502S26X.

How does thermal shutdown behave during continuous overload of the FAN2502S26X?

Under continuous overload, the FAN2502S26X enters thermal shutdown at 150°C junction temperature, disabling VOUT until die temperature drops below the hysteresis threshold (~140°C). If overload persists, this causes thermal cycling - repeated shutdown/re-enable - which can degrade reliability. To prevent this, ensure PCB copper area and airflow meet θ_JA ≤ 220°C/W spec, or use EN pin to force shutdown during fault conditions in FAN2502S26X designs.