Diodes Incorporated FMMTA14TA

Overview

FMMTA14TA 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 = 10,000–20,000 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 FMMTA14TA datasheet, FMMTA14TA pinout, FMMTA14TA application, or FMMTA14TA equivalent, key selection criteria include guaranteed high DC current gain at low base drive, low V_CE(sat) under 0.9 V at 100 mA, SOT-23 footprint compatibility, and verified Darlington configuration for reduced base current requirements in discrete logic-level interfacing.

Technical Context

This Darlington pair integrates two NPN transistors monolithically to deliver high current gain while maintaining single-transistor pinout and thermal behavior. It operates with V_BE(on) up to 2.0 V at I_C = 100 mA and exhibits V_CE(sat) ≤ 0.9 V under same conditions, enabling efficient low-voltage switching.

The device supports operation from −55 °C to +150 °C junction temperature, features V_CB0 = 40 V and V_ES = 10 V, and is characterized under pulsed test conditions (300 µs pulse width, ≤2% duty cycle) to ensure stable parameter reporting across temperature.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package with gull-wing leads; standardized 3-pin footprint (EIAJ SC-59), 1.3 mm × 2.9 mm body size, 0.95 mm height, and 0.95 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FMMTA14TA, MMBTA14 offers identical electrical performance with assured lifecycle support, while ULN2003A trades single-device simplicity for integrated multi-channel functionality-making MMBTA14 the preferred drop-in upgrade and ULN2003A a system-level alternative for arrayed loads.

Availability

FMMTA14TA is available at Aetrix Electronics and suitable for LED driver stages, microcontroller GPIO expansion, industrial sensor interfaces, and low-power relay drivers requiring stable component supply and legacy design continuity.

Supply support for FMMTA14TA 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, high-efficiency components for industrial, computing, and consumer markets.

The FMMTA series belongs to Diodes' legacy discrete transistor portfolio, designed specifically for compact, high-gain switching in space-constrained PCBs where Darlington performance is needed without hybrid module complexity.

FAQ

Is FMMTA14TA still in active production?

No-FMMTA14TA is officially discontinued per Diodes Incorporated's product change notice. It remains available through authorized distributors with remaining legacy stock, and MMBTA14 is the designated active replacement with identical specifications and SOT-23 packaging.

What is the maximum safe base current for continuous operation?

The absolute maximum base current is not explicitly specified, but based on I_C = 300 mA and minimum h_FE = 10,000, the recommended continuous base current is ≤30 µA. For pulsed switching at 100 mA, I_B = 0.1 mA is validated per datasheet test conditions.

Can FMMTA14TA replace a standard NPN transistor like BC847?

No-it cannot serve as a direct substitute due to its Darlington structure: V_BE(on) is ~1.4–2.0 V (vs. ~0.7 V for BC847), and it requires significantly less base current but introduces higher saturation voltage and slower turn-off. Circuit redesign is required for biasing and timing.

Does FMMTA14TA include built-in base-emitter resistors?

No-FMMTA14TA is a bare Darlington transistor without integrated base resistors. External base current limiting must be provided via a series resistor, calculated using V_BE(on) ≈ 1.6 V and desired I_B, typically 10–100 µA for switching applications.