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

Diodes Incorporated FMMT618TC

Name: FMMT618TC
Brand: Diodes Incorporated
SKU: FMMT618TC
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FMMT618TC

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

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

Datasheet:: FMMT618TC.pdf

Description:: TRANS NPN 20V 2.5A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Inventory:4,085

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Product details

Overview

FMMT618TC from Diodes Incorporated is a 20V NPN silicon low-saturation transistor in SOT23 package, designed for high-current switching with 2.5A continuous collector current, 50mΩ R_CE(SAT), and AEC-Q101 qualification. It serves as a compact, thermally efficient switch in DC-DC modules, gate drivers, and LED drivers where low conduction loss and fast switching are critical.

For engineers reviewing the FMMT618TC datasheet, FMMT618TC pinout, FMMT618TC application, or FMMT618TC equivalent, key selection criteria include V_CEO = 20V, I_C = 2.5A, R_CE(SAT) ≤ 150mΩ at 2.5A/50mA drive, h_FE ≥ 150 at 2A, and SOT23 thermal performance under pulsed and continuous operation.

Technical Context

This NPN transistor operates in linear or saturated switching mode with BV_CEO = 20V and VEBO = 7V, enabling use in low-voltage power control circuits up to 20V rail. Its h_FE is characterized from 10mA to 6A, supporting stable current gain across wide load ranges.

With t_on = 170ns and t_off = 400ns under 10mA drive, it delivers fast switching suitable for PWM-based LED and gate driving. The 625mW steady-state power dissipation (R_θJA = 200°C/W on 25mm × 25mm FR4) ensures reliable operation without forced cooling in space-constrained designs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	20 V - Maximum allowable collector-emitter voltage before breakdown; sets upper limit for supply rail compatibility.
I_C (continuous)	2.5 A - Continuous current-handling capability; supports high-side/low-side switching in 2A-class loads.
R_CE(SAT)	≤150 mΩ at I_C = 2.5A, I_B = 50mA - Low on-resistance minimizes conduction loss and self-heating in power stages.
h_FE	≥150 at I_C = 2A, V_CE = 2V - Ensures sufficient current gain for reliable saturation with moderate base drive.
f_T	100–140 MHz - Enables stable high-frequency switching up to ~10MHz with adequate gain margin.
t_off	400 ns - Defines minimum dead-time requirements in half-bridge or synchronous rectifier topologies.

Pinout & Package

Package: SOT23 - Surface-mount plastic case (2.9mm × 1.3mm × 1.0mm), UL 94V-0 rated, moisture sensitivity level 1, matte tin-plated leads.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Reference node for base drive; connects to ground or low-side return path in common-emitter configuration.
2 (Base)	Control input	Accepts TTL/CMOS-compatible drive; requires ≥50mA peak for full saturation at 2.5A collector current.
3 (Collector)	Current source terminal	Connects to load or power rail; carries full switched current and dissipates majority of junction heat.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test conditions.
Low R_CE(SAT)	50mΩ typical at I_C = 1A/I_B = 10mA - reduces I²R losses by >40% vs. standard small-signal transistors at same current.
High h_FE up to 6A	h_FE ≥ 100 at I_C = 6A - maintains controllability in overload or pulse-current scenarios without drive starvation.
Green compound & RoHS	Halogen- and antimony-free molding compound (<900ppm Br+Cl, <1000ppm Sb); compliant with EU RoHS 2 directive.

Applications

DC-DC Converter Switching Stage

LED Constant-Current Driver

Use Scenario: High-efficiency buck converter operating at 500kHz with 12V input and 5V/2A output.

IC Role / Device Role / Timing Role: Low-side synchronous switch replacing MOSFET in cost-sensitive designs; handles 2.5A peak inductor current.

Use Value: 150mΩ R_CE(SAT) limits conduction loss to <1.2W at 2.5A, enabling passive cooling on compact PCBs.

Use Scenario: Automotive interior lighting module driving 10× high-brightness LEDs in series.

IC Role / Device Role / Timing Role: Constant-current shunt regulator transistor in linear LED driver topology.

Use Value: Stable h_FE over −40°C to +105°C ensures consistent current regulation across vehicle cabin temperature range.

Gate Driver for Power MOSFETs

Industrial PLC Output Stage

Use Scenario: Low-voltage logic-level gate driver stage controlling 30V N-channel MOSFET in motor control H-bridge.

IC Role / Device Role / Timing Role: Fast-turn-on/off bipolar switch providing 10mA–50mA peak gate charge/discharge current.

Use Value: 170ns t_on/400ns t_off enables clean gate transitions with minimal shoot-through risk at 100kHz PWM.

Use Scenario: 24V DC digital output module in industrial automation controller delivering 2A to solenoid valves.

IC Role / Device Role / Timing Role: Final-stage power switch interfacing microcontroller GPIO to inductive load.

Use Value: AEC-Q101 qualification and 150°C T_JMAX ensure long-term reliability in unventilated control cabinets.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN low-saturation transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZXTN2020ZTA	V_CEO = 20V, I_C = 3A, R_CE(SAT) = 45mΩ @ 2A - slightly lower saturation voltage but higher f_T (200MHz).	Higher f_T supports faster switching; less optimized for high-temperature h_FE stability above 85°C.	Prefer when switching frequency exceeds 1MHz or when tighter R_CE(SAT) tolerance is required.
MMBT6427LT1G	V_CEO = 20V, I_C = 1A, R_CE(SAT) = 120mΩ @ 1A - lower current rating and higher saturation resistance.	Not rated for 2.5A continuous; unsuitable for DC-DC or high-current LED drivers.	Select only for signal-level or <1A load switching where footprint compatibility is prioritized over power capability.

Compared with ZXTN2020ZTA and MMBT6427LT1G, the FMMT618TC offers superior thermal robustness (150°C T_JMAX) and verified h_FE hold-up at 6A, making it preferred for automotive and industrial applications demanding sustained high-current conduction and AEC-Q101 compliance.

Availability

FMMT618TC is available at Aetrix Electronics and suitable for DC-DC modules, LED drivers, and gate driver circuits requiring stable component supply, automotive-grade reliability, and SOT23 footprint compatibility.

Supply support for FMMT618TC 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 power management, signal integrity, and protection solutions.

The FMMT618TC belongs to Diodes' AEC-Q101-qualified low-saturation transistor product line, engineered for automotive and industrial power switching where low R_CE(SAT), high current gain, and thermal resilience are essential.

FAQ

What is the maximum continuous collector current for FMMT618TC?

The FMMT618TC supports 2.5A continuous collector current at T_A = +25°C with derating to zero at +150°C ambient. This rating assumes surface mounting on 25mm × 25mm FR4 PCB with 1 oz copper; actual usable current depends on board layout and airflow.

Is FMMT618TC suitable for automotive applications?

Yes - the FMMT618TC is AEC-Q101 qualified and PPAP capable. It meets automotive reliability requirements including temperature cycling, high-temperature reverse bias, and electrostatic discharge testing, and is marked "FMMT618QTA" for automotive-grade variants.

How does the hFE behavior change at high collector currents?

h_FE remains ≥150 at I_C = 2A and ≥100 at I_C = 6A (pulsed), demonstrating strong current gain retention under heavy loading. This allows predictable base drive design without excessive overdrive, reducing MCU GPIO stress.

What is the thermal resistance from junction to ambient under standard mounting?

R_θJA is 200°C/W for steady-state operation on a 25mm × 25mm FR4 board with single-sided 1 oz copper. For short pulses (t ≤ 5 sec), R_θJA improves to 155°C/W, enabling brief 6A peak current handling without exceeding 150°C junction temperature.

FMMT618TC 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

Current - Collector (Ic) (Max):: 2.5 A

Voltage - Collector Emitter Breakdown (Max):: 20 V

Vce Saturation (Max) @ Ib, Ic:: 200mV @ 50mA, 2.5A

Current - Collector Cutoff (Max):: 100nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 200 @ 2A, 2V

Power - Max:: 625 mW

Frequency - Transition:: 140MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

FMMT618TC FAQ

1.How can I place an order for FMMT618TC through Aetrix?

Please submit a Request for Quotation (RFQ) for FMMT618TC 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 FMMT618TC reliable?

The price and inventory of FMMT618TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMT618TC is usually 5 days.

3.What payment methods are accepted for FMMT618TC?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMT618TC transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FMMT618TC?

FMMT618TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FMMT618TC 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 FMMT618TC?

For technical support, including FMMT618TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMT618TC requirements.

6.How does Aetrix verify that FMMT618TC is sourced from the original manufacturer or authorized distributors?

All FMMT618TC 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 FMMT618TC meets industry standards.

7.What is the process for return or replacement of FMMT618TC?

All FMMT618TC units undergo pre-shipment inspection (PSI). If there is an issue with FMMT618TC, 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 FMMT618TC part is unused and in its original packaging.

Return procedure for FMMT618TC:

1.Submit a request within 90 days.

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

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