Diodes Incorporated FMMTA13TA

Overview

FMMTA13TA from Diodes Incorporated is an NPN silicon planar Darlington transistor in SOT-23 package, rated for V_CEO = 40 V, I_C = 300 mA, and h_FE = 5,000–10,000 at I_C = 10–100 mA, used in low-power switching and signal amplification circuits such as LED drivers and sensor interface stages.

For engineers reviewing the FMMTA13TA datasheet, FMMTA13TA pinout, FMMTA13TA application, or FMMTA13TA equivalent, key selection criteria include guaranteed high DC current gain at low base drive, low V_CE(sat) ≤ 0.9 V at I_C = 100 mA, SOT-23 footprint compatibility, and complementary PNP pairing with FMMTA63.

Technical Context

This Darlington pair integrates two NPN transistors monolithically to deliver high current gain while maintaining single-transistor control simplicity. It operates with a typical V_BE(on) of 1.4–2.0 V and supports pulsed operation up to 300 µs duty cycle ≤2%.

The device features V_CES = 40 V, enabling use in 24 V rail applications with margin, and exhibits I_CBO ≤ 100 nA at V_CB = 30 V, ensuring low leakage in standby-sensitive designs.

Key Specifications

Pinout & Package

Package: SOT-23 (TO-236AB), surface-mount, 3-terminal plastic case with standard lead pitch and thermal pad layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Darlington transistor applications.

Compared with FMMTA13TA, MMBTA13 offers lower saturation voltage for improved thermal performance in sustained switching, while FMMTA63 serves as its designated PNP complement-not a drop-in substitute-enabling symmetrical output topologies.

Availability

FMMTA13TA is available at Aetrix Electronics and suitable for LED driver design, sensor interface circuits, relay control modules, and standby power management requiring stable component supply and legacy footprint continuity.

Supply support for FMMTA13TA 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, cost-optimized components for industrial, computing, and consumer markets.

FMMTA13TA belongs to the FMMT/FMMTA series of high-gain Darlington transistors designed specifically for low-base-drive switching and linear amplification in space-constrained SOT-23 applications.

FAQ

Is FMMTA13TA still in active production?

No - FMMTA13TA is officially obsolete per Diodes Incorporated's product discontinuation notice. Aetrix Electronics maintains limited legacy stock and supports transition to MMBTA13, which shares identical pinout, electrical specs, and enhanced thermal performance under continuous operation.

What is the maximum safe operating current for FMMTA13TA in DC mode?

The absolute maximum continuous collector current is 300 mA, but derating is required above 25°C ambient. At 70°C board temperature, usable I_C drops to ~180 mA due to P_tot = 330 mW and R_θJA ≈ 400°C/W for SOT-23 on standard FR4.

Can FMMTA13TA replace a standard single NPN transistor like BC847?

No - FMMTA13TA is a Darlington pair with ~1.4–2.0 V V_BE(on) and much higher h_FE, making it unsuitable for linear amplifier biasing or fast-switching applications where low V_BE and speed matter. It replaces only high-gain, low-drive switching roles.

Does FMMTA13TA require a base resistor when driven by a 3.3 V MCU GPIO?

Yes - a series base resistor is mandatory to limit I_B and prevent damage. For 100 mA I_C, assuming h_FE = 5,000, I_B ≈ 20 µA; with V_GPIO = 3.3 V and V_BE ≈ 1.6 V, a 82 kΩ resistor sets appropriate drive while allowing margin for process variation.