Diodes Incorporated FMMTA13TC

Overview

FMMTA13TC 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 (min) at I_C = 10 mA / V_CE = 5 V, used in low-power switching and signal amplification circuits such as LED drivers and sensor interface stages.

For engineers reviewing the FMMTA13TC datasheet, FMMTA13TC pinout, FMMTA13TC application, or FMMTA13TC equivalent, key selection criteria include guaranteed high DC current gain at low base drive, V_CES = 40 V capability, SOT-23 thermal performance under pulsed operation, and direct replacement path to MMBTA13.

Technical Context

This Darlington pair integrates two NPN transistors monolithically to deliver high current gain with minimal base drive-enabling efficient low-voltage control of moderate loads. It operates with V_BE(on) = 1.4–2.0 V and V_CE(sat) = 0.9 V at I_C = 100 mA / I_B = 0.1 mA, supporting reliable saturation in logic-level driven switches.

The device features V_CB0 = 40 V, V_CES = 40 V, and I_CBO ≤ 100 nA at V_CB = 30 V, ensuring robust off-state isolation and stable gain across -55°C to +150°C junction temperature range.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package with standard pin assignment: Emitter (Pin 1), Base (Pin 2), Collector (Pin 3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with FMMTA13TC, MMBTA13 offers identical electrical behavior with enhanced process control and availability, while FMMTA63 serves a fundamentally different circuit role-making MMBTA13 the preferred upgrade path for continuity and reliability.

Availability

FMMTA13TC is available at Aetrix Electronics and suitable for LED driver circuits, sensor interface modules, relay interface boards, and low-voltage level-shifting applications requiring stable component supply and legacy design compatibility.

Supply support for FMMTA13TC 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 components for industrial, computing, and consumer markets.

The FMMTA series belongs to Diodes' general-purpose bipolar transistor product line, designed specifically for cost-sensitive, space-constrained switching and amplification tasks in SMT-based equipment.

FAQ

Is FMMTA13TC still in active production?

No-FMMTA13TC is officially obsolete per Diodes Incorporated's discontinuation notice. It is superseded by MMBTA13, which maintains identical electrical specifications, SOT-23 packaging, and full RoHS compliance. Aetrix Electronics holds legacy stock for repair and maintenance use, but new designs should adopt MMBTA13.

What is the maximum safe continuous collector current at 85°C ambient?

At T_amb = 85°C, the SOT-23 package requires linear derating from 300 mA at 25°C. With P_tot = 330 mW and θ_JA ≈ 300°C/W, maximum I_C drops to approximately 180 mA to maintain T_j ≤ 150°C. Derating curves are documented in the FMMT38A reference datasheet.

Can FMMTA13TC replace a standard NPN transistor like BC847 in a switching circuit?

Yes-but only if the circuit benefits from higher h_FE and can accommodate higher V_BE(on) (1.4–2.0 V vs. ~0.7 V). Due to its Darlington structure, FMMTA13TC draws more base current than a single transistor at equivalent collector current, and exhibits slower turn-off. Verify timing margins and base drive capability before substitution.

Does FMMTA13TC require an external flyback diode when driving inductive loads?

While not strictly required due to V_CES = 40 V, an external flyback diode is strongly recommended for relay or solenoid loads to clamp inductive kickback and prevent premature device failure. The Darlington structure has lower ruggedness against voltage transients than single transistors, and datasheet testing does not guarantee unclamped inductive switching endurance.