onsemi FAN2504S30X

Overview

FAN2504S30X from Fairchild Semiconductor is a 3.0 V fixed-output CMOS low-dropout (LDO) voltage regulator in SOT-23-5 package, delivering up to 200 mA output current with 200 mV dropout at full load, 75 µA ground current at 200 mA, and enable/shutdown control - designed for power management in portable battery-powered systems such as cellular handsets and notebook computers.

For engineers reviewing the FAN2504S30X datasheet, pinout, applications, or equivalent options, key selection criteria include its 3.0 V fixed output, BYP pin for noise reduction via 470 pF capacitor, thermal shutdown at 150°C, ±2% output accuracy, and compatibility with ceramic, tantalum, or aluminum electrolytic output capacitors (1 µF min, ESR 10 mΩ–10 Ω).

Technical Context

The FAN2504S30X uses a P-channel MOSFET series pass element with ~1 Ω on-resistance, enabling ultra-low dropout performance compared to bipolar LDOs. Its CMOS error amplifier features low input bias current and references a 1.3 V (typ) bandgap, ensuring stable regulation across temperature and load.

Pin 4 is configured as BYP (bypass), not ADJ or ERR - allowing connection of a 470 pF capacitor to reduce output noise. Loop stability is maintained across wide ESR ranges (10 mΩ to 10 Ω), eliminating strict capacitor type dependencies typical of older LDO architectures.

Key Specifications

Pinout & Package

SOT-23-5 (SC-74A) surface-mount package: 2.9 mm × 1.6 mm × 1.1 mm body, 0.95 mm lead pitch, gull-wing leads. Thermal resistance θ_JA ≈ 220°C/W (min footprint), improved with PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-3002E/TT and TCS2103-3.0, the FAN2504S30X uniquely balances low dropout (200 mV), low noise (via BYP), and logic-controlled enable - making it optimal for noise-critical, battery-constrained, and dynamically powered subsystems.

Availability

FAN2504S30X is available at Aetrix Electronics and suitable for cellular handset RF biasing, laptop USB peripheral powering, digital camera image sensor regulation, and PDA application processor core supply requiring stable component supply, long-term lifecycle support, and consistent parametric performance.

Supply support for FAN2504S30X 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 designer and manufacturer of high-performance analog and power ICs, acquired by ON Semiconductor in 2016; its legacy LDO portfolio remains widely deployed in portable electronics.

The FAN2504/FAN2505 family was engineered specifically for GSM/TDMA handsets and portable computing, prioritizing micropower operation, low dropout, and compact SOT-23-5 integration to meet stringent size and battery-life requirements.

FAQ

What is the exact output voltage tolerance and temperature drift of the FAN2504S30X?

The FAN2504S30X delivers a nominal 3.0 V output with ±2% initial accuracy over load, line, and temperature (–40°C to +125°C). Typical output voltage variation across temperature is ±0.5% (2.985 V to 3.015 V) at 100 µA load, as confirmed by the "Output Voltage vs. Temperature" curve in the datasheet (Rev. 1.0.8, p.8). This stability is enabled by the low-drift 1.3 V bandgap reference and CMOS error amplifier design.

Can the FAN2504S30X be used with ceramic output capacitors, and what is the minimum recommended value?

Yes, the FAN2504S30X is fully stable with ceramic output capacitors due to its low ESR sensitivity. The datasheet specifies stable operation with ESR values from 10 mΩ to 10 Ω, and recommends a minimum output capacitance of 1 µF. X7R or Y5V dielectric ceramics are preferred for their low ESR, small footprint, and favorable temperature coefficient - no additional series resistance or special capacitor types are required.

What is the function of Pin 4 (BYP) on the FAN2504S30X, and how should it be connected?

Pin 4 on the FAN2504S30X is the BYP (bypass) terminal - a high-impedance node connected internally to the bandgap reference. It must be tied to GND via a 470 pF ceramic or film capacitor to reduce output noise, particularly in the 10 Hz–1 kHz band. Leakage-prone capacitors must be avoided; high-quality C0G/NP0 or X7R ceramics are recommended. Omitting the BYP capacitor increases output noise to >10 µV/√Hz, degrading performance in noise-sensitive analog circuits.

Does the FAN2504S30X include thermal protection, and at what junction temperature does it activate?

Yes, the FAN2504S30X incorporates internal thermal shutdown that activates when the silicon junction temperature reaches 150°C. Once triggered, the output is disabled until the die cools below the hysteresis threshold (~140°C), at which point regulation resumes automatically. This protection operates independently of the EN pin and guards against sustained overload, inadequate PCB copper, or high ambient temperatures - preventing permanent device failure.

What are the enable logic thresholds and shutdown current specifications for the FAN2504S30X?

The FAN2504S30X EN pin has a logic-low threshold (V_IL) of ≤ 0.4 V and logic-high threshold (V_IH) of ≥ 1.4 V at 25°C, ensuring compatibility with both 1.8 V and 3.3 V GPIOs. When EN is pulled low (<0.4 V), the device enters shutdown mode with ground current reduced to ≤ 1 µA - verified across –40°C to +125°C. Leaving EN floating is prohibited and causes unpredictable output behavior.