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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

Diodes Incorporated FMMTA14TC

Name: FMMTA14TC
Brand: Diodes Incorporated
SKU: FMMTA14TC
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FMMTA14TC

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: FMMTA14TC.pdf

Description:: TRANS NPN DARL 40V 0.3A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

FMMTA14TC from Diodes Incorporated is an NPN silicon planar Darlington transistor in SOT-23 package, with V_CEO = 40 V, h_FE = 10,000–20,000 (at I_C = 10–100 mA), and V_CE(sat) ≤ 0.9 V at I_C = 100 mA / I_B = 0.1 mA. It serves as a high-gain switching element in low-power interface and signal amplification circuits.

For engineers reviewing the FMMTA14TC datasheet, FMMTA14TC pinout, FMMTA14TC application, or FMMTA14TC equivalent, key selection criteria include guaranteed h_FE range at two collector current levels, low saturation voltage under defined drive conditions, and SOT-23 thermal and layout compatibility for space-constrained PCBs.

Technical Context

This Darlington pair integrates two NPN transistors monolithically to deliver high DC current gain while maintaining single-transistor footprint and bias simplicity. Its V_CES = 40 V and V_EBO = 10 V define safe operating limits for emitter-referenced switching topologies.

The device exhibits pulsed test conditions (300 µs pulse width, ≤2% duty cycle) for h_FE and V_CE(sat) measurements, indicating design intent for intermittent or duty-cycled operation rather than continuous linear amplification.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum allowable collector-emitter voltage with base open; defines safe switching margin in relay drivers or logic-level interfaces.
h_FE	10,000–20,000 - High DC current gain at I_C = 10 mA and 100 mA; enables microampere-level base drive for 100 mA load switching.
V_CE(sat)	≤0.9 V at I_C = 100 mA / I_B = 0.1 mA - Low saturation voltage ensures minimal power loss and heat generation in on-state switching.
I_C (cont.)	300 mA - Continuous collector current rating; sets upper bound for sustained load current handling in SOT-23 package.
P_tot	330 mW at T_amb = 25°C - Total power dissipation limit; requires thermal derating above ambient temperature.
T_j/T_stg	−55°C to +150°C - Junction and storage temperature range; supports operation in industrial and automotive under-hood environments.

Pinout & Package

Package: SOT-23 (TO-236AB), surface-mount, 3-terminal plastic package with standard lead pitch of 0.95 mm and body dimensions 2.9 mm × 1.3 mm × 1.0 mm.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emitting terminal of Darlington pair	Connected to ground or low-side return path; carries full load current and must be routed with adequate copper area for thermal relief.
2 (Base)	Control input for Darlington pair	Accepts low-current drive (e.g., MCU GPIO); internal resistor network not present - external base resistor required for current limiting.
3 (Collector)	High-side output terminal	Switches load to V_CC; voltage rating limited by V_CEO = 40 V and V_CES = 40 V under open-base condition.

Key Features

Feature	Design Value
High h_FE at dual current points	10,000 @ I_C = 10 mA and 20,000 @ I_C = 100 mA - Enables consistent gain across light and moderate load conditions without gain collapse.
Low V_CE(sat) under rated drive	≤0.9 V @ I_C = 100 mA / I_B = 0.1 mA - Reduces conduction loss to <90 mW, easing thermal management in compact layouts.
SOT-23 footprint compatibility	Standard JEDEC TO-236AB outline - Allows drop-in replacement in existing designs using MMBTA14, FMMTA13, or similar SOT-23 NPN switches.
Wide operating temperature range	−55°C to +150°C - Qualified for use in extended-temperature industrial control modules and automotive cabin electronics.

Applications

LED Driver Circuit

Microcontroller Interface

Use Scenario: Driving 20 mA indicator LEDs from 3.3 V or 5 V logic rails with minimal GPIO current draw.

IC Role / Device Role / Timing Role: High-gain current amplifier enabling direct MCU GPIO control without external driver IC.

Use Value: Delivers 20 mA LED current with only 2 µA base drive (due to h_FE ≥10,000), preserving MCU I/O budget and reducing BOM count.

Use Scenario: Level-shifting and isolating 1.8 V/3.3 V logic outputs to control 12 V solenoids or relays.

IC Role / Device Role / Timing Role: Low-side switch translating logic-level signals into higher-voltage load control paths.

Use Value: V_CEO = 40 V and V_CE(sat) ≤0.9 V ensure reliable turn-on of 12 V inductive loads while minimizing heat rise in dense PCB layouts.

Industrial Sensor Interface

Power Supply Enable Switch

Use Scenario: Amplifying weak current-mode outputs (e.g., 4–20 mA loop receivers) into clean digital logic signals.

IC Role / Device Role / Timing Role: Signal-conditioning Darlington stage converting analog sensor current into saturated logic-level output.

Use Value: High h_FE maintains stable switching threshold across temperature, avoiding false triggers in noisy factory environments.

Use Scenario: Enabling/disabling auxiliary 5 V or 3.3 V supply rails in multi-rail embedded systems.

IC Role / Device Role / Timing Role: Low-loss enable switch placed between regulator output and downstream circuitry.

Use Value: P_tot = 330 mW and low V_CE(sat) allow continuous 300 mA rail switching without heatsinking in space-constrained modules.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBTA14	Same SOT-23 package; h_FE = 10,000–20,000 at I_C = 10 mA, but no specified h_FE at I_C = 100 mA; V_CE(sat) = 0.75 V typical at I_C = 100 mA.	Optimized for lower-saturation, moderate-gain operation; less suitable for high-current gain stability verification.	Select when lower V_CE(sat) is prioritized over guaranteed high-current h_FE.
FMMTA13	Same family, same package; h_FE = 5,000–10,000 at I_C = 10 mA and 10,000 at I_C = 100 mA; V_CE(sat) = 0.9 V max at same conditions.	Lower minimum gain makes it less robust for marginal base drive or high-temperature gain degradation.	Select only if system-level gain margin allows reduction from 10K to 5K minimum at light loads.

Compared with MMBTA14 and FMMTA13, FMMTA14TC provides the highest guaranteed h_FE across both light and heavy load conditions, making it preferable for designs requiring predictable turn-on behavior with weak drive sources or wide temperature excursions.

Availability

FMMTA14TC is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller interface modules, and industrial sensor interfaces requiring stable component supply and long-term design continuity.

Supply support for FMMTA14TC 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 applications.

The FMMT/FMMTA series targets space-constrained, high-gain switching applications where SOT-23 footprint and Darlington performance are jointly required - particularly in legacy-compatible replacements and cost-sensitive interface designs.

FAQ

Is FMMTA14TC a Darlington transistor?

Yes, FMMTA14TC is a monolithic NPN Darlington transistor consisting of two cascaded NPN stages on a single die. This configuration delivers high DC current gain (h_FE up to 20,000) while retaining the three-terminal SOT-23 pinout and bias simplicity of a standard transistor.

What is the maximum continuous collector current for FMMTA14TC?

The maximum continuous collector current is 300 mA at T_amb = 25°C. Derating is required above this ambient temperature per the thermal resistance specification (R_θJA ≈ 379°C/W), and actual usable current depends on PCB copper area, airflow, and duty cycle in pulsed applications.

Does FMMTA14TC have built-in base resistors?

No, FMMTA14TC does not include integrated base resistors. It is a bare Darlington transistor requiring an external series base resistor to limit drive current. The base terminal connects directly to the input of the first transistor stage, and proper resistor sizing is essential to avoid overdriving or thermal runaway.

Can FMMTA14TC replace FMMTA13 in existing designs?

Yes, FMMTA14TC is pin-compatible and electrically compatible with FMMTA13, offering higher minimum h_FE (10,000 vs. 5,000 at I_C = 10 mA) and identical V_CE(sat) and voltage ratings. No layout or schematic changes are needed, and the upgrade improves gain margin and noise immunity in marginal drive conditions.

FMMTA14TC Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN - Darlington

Current - Collector (Ic) (Max):: 300 mA

Voltage - Collector Emitter Breakdown (Max):: 40 V

Vce Saturation (Max) @ Ib, Ic:: 900mV @ 100µA, 100mA

Current - Collector Cutoff (Max):: 100nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 20000 @ 100mA, 5V

Power - Max:: 330 mW

Frequency - Transition:: -

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

FMMTA14TC FAQ

1.How can I place an order for FMMTA14TC through Aetrix?

Please submit a Request for Quotation (RFQ) for FMMTA14TC on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for FMMTA14TC reliable?

The price and inventory of FMMTA14TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMTA14TC is usually 5 days.

3.What payment methods are accepted for FMMTA14TC?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMTA14TC transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FMMTA14TC?

FMMTA14TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FMMTA14TC order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for FMMTA14TC?

For technical support, including FMMTA14TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMTA14TC requirements.

6.How does Aetrix verify that FMMTA14TC is sourced from the original manufacturer or authorized distributors?

All FMMTA14TC products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that FMMTA14TC meets industry standards.

7.What is the process for return or replacement of FMMTA14TC?

All FMMTA14TC units undergo pre-shipment inspection (PSI). If there is an issue with FMMTA14TC, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The FMMTA14TC part is unused and in its original packaging.

Return procedure for FMMTA14TC:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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