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

Diodes Incorporated FMMT38CTA

Name: FMMT38CTA
Brand: Diodes Incorporated
SKU: FMMT38CTA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FMMT38CTA

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

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

Datasheet:: FMMT38CTA.pdf

Description:: TRANS NPN DARL 60V 0.3A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Inventory:25,897

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Product details

Overview

FMMT38CTA from Diodes Incorporated is a 60V NPN medium-power Darlington transistor in SOT23 package, featuring BV_CEO > 60 V, I_C = 300 mA continuous, h_FE > 10,000 at I_C = 500 mA, V_CE(SAT) = 0.89 V (typ) at 800 mA pulse, and AEC-Q101 qualification for automotive reliability. It serves as a high-gain switching element in low-voltage power control circuits such as LED drivers and relay interfaces.

For engineers reviewing the FMMT38CTA datasheet, FMMT38CTA pinout, FMMT38CTA application, or FMMT38CTA equivalent, key selection criteria include Darlington gain linearity at high current, thermal derating on FR4 PCBs, SOT23 footprint compatibility, and compliance with automotive-grade ESD (HBM 2 kV) and RoHS/Green requirements.

Technical Context

This Darlington pair integrates two NPN transistors monolithically to deliver high DC current gain while maintaining single-SOT23 footprint. Its structure enables low base drive requirements-e.g., 8 mA IB drives 800 mA IC-with V_BE(ON) = 1.3–1.8 V at full pulse current.

The device operates across –55°C to +150°C, supports pulsed operation up to 300 µs/2% duty cycle, and exhibits R_θJA = 378°C/W on 15 mm × 15 mm 1 oz copper FR4-critical for thermally constrained space-limited designs.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	60 V - Maximum safe collector-emitter voltage before breakdown; defines upper rail limit in 24 V industrial control switches.
h_FE	10,000 min at I_C = 500 mA - Enables microcontroller GPIO-level base drive (e.g., 3.3 V/5 V logic) to switch >500 mA loads directly.
V_CE(SAT)	0.89 V typ at I_C = 800 mA, I_B = 8 mA - Limits conduction loss to <710 mW at peak pulse, reducing thermal stress in compact layouts.
P_D	330 mW - Power dissipation limit on standard FR4; requires thermal derating above +25°C ambient per published curve.
R_θJA	378°C/W - Junction-to-ambient thermal resistance under JEDEC test board conditions; informs heatsinking necessity for sustained >150 mA operation.
ESD HBM	2,000 V - Human Body Model rating per JESD22-A114; suitable for assembly in non-EPA environments without special handling.

Pinout & Package

Package: SOT23 - surface-mount plastic case, 0.008 g weight, UL 94V-0 rated, matte tin-plated leads solderable per MIL-STD-202 Method 208.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	E	Low-side return path; connected to ground or load common; carries full load current.
2 (Base)	B	Control input; requires ~8 mA for full 800 mA saturation; sensitive to ESD due to high h_FE.
3 (Collector)	C	High-side output; connects to positive rail or load anode; withstands up to 60 V reverse bias.

Key Features

Feature	Design Value
Darlington architecture	Monolithic NPN-NPN pair delivering h_FE ≥ 10k at 500 mA-reduces base drive circuit complexity vs. discrete cascaded stages.
AEC-Q101 qualification	Validated for automotive applications including engine control modules and body electronics-ensures reliability under temperature cycling and vibration stress.
Green / Halogen-free	Meets <900 ppm Br, <900 ppm Cl, <1000 ppm Sb limits-supports environmental compliance in EU and global OEM supply chains.
SOT23 footprint	Standardized 3-pin outline (2.9 mm × 1.3 mm × 1.0 mm) enabling drop-in replacement in legacy PCBs designed for MMBT3904 or similar small-signal transistors.

Applications

Automotive Door Module

Industrial PLC Output Stage

Use Scenario: Driving 12 V solenoid locks and indicator LEDs in vehicle door control units.

IC Role / Device Role / Timing Role: High-gain Darlington switch providing direct GPIO-compatible actuation of 300–500 mA loads without external driver ICs.

Use Value: Eliminates need for dual-stage BJT/MOSFET buffers, reducing BOM count and PCB area while meeting AEC-Q101 reliability targets.

Use Scenario: Switching 24 V DC solenoids and pneumatic valves in programmable logic controller output cards.

IC Role / Device Role / Timing Role: Medium-power interface transistor translating 5 V logic signals into robust 300 mA load current capability.

Use Value: Delivers stable saturation (V_CE(SAT) ≤ 1.25 V) across –40°C to +85°C operating range, ensuring deterministic timing in real-time control loops.

LED Backlight Driver

Relay Coil Interface

Use Scenario: Controlling parallel strings of white LEDs in display backlighting for medical panels and HMIs.

IC Role / Device Role / Timing Role: Constant-current switch regulating LED string current via PWM-controlled base drive.

Use Value: High h_FE ensures minimal base current ripple during PWM dimming, preserving LED color consistency and reducing EMI.

Use Scenario: Energizing 12 V/24 V electromagnetic relays in HVAC control boards and power distribution units.

IC Role / Device Role / Timing Role: Low-impedance coil driver with fast turn-off aided by internal Baker clamp (implied by V_CE(SAT) spec).

Use Value: Reduces relay release delay by minimizing storage time-critical for safety-critical interlock sequencing in industrial machinery.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX1051A	Higher V_CEO = 100 V, lower h_FE = 2,000–5,000, SOT89 package	Requires larger PCB area; better suited for higher-voltage flyback snubbing	Select when >60 V blocking is required and thermal mass allows SOT89 mounting.
MMBT3904DW	Single NPN, h_FE = 100–300, no Darlington gain, same SOT23 footprint	Lacks high-current drive capability; needs external driver stage for >100 mA loads	Choose only for low-current signal switching where gain >10k is unnecessary.

Compared with ZTX1051A and MMBT3904DW, FMMT38CTA uniquely balances AEC-Q101 compliance, SOT23 size, and Darlington-level gain-making it optimal for space-constrained automotive and industrial switching where base drive simplicity and thermal efficiency are prioritized over ultra-high voltage rating or cost-per-transistor.

Availability

FMMT38CTA is available at Aetrix Electronics and suitable for automotive door modules, industrial PLC output stages, LED backlight drivers, and relay coil interfaces requiring stable component supply with AEC-Q101 traceability and green material compliance.

Supply support for FMMT38CTA 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 automotive, industrial, and consumer markets.

FMMT38CTA belongs to Diodes' AEC-Q101-qualified medium-power transistor product line, engineered specifically for robust, high-gain switching in space-constrained automotive body electronics and industrial control systems.

FAQ

What is the maximum continuous collector current for FMMT38CTA?

The maximum continuous collector current is 300 mA at T_A = +25°C. Derating is required above this temperature per the published thermal curve-e.g., ~225 mA at +70°C ambient on standard FR4. This rating reflects steady-state conduction without pulse duty cycle limitations.

Does FMMT38CTA have integrated protection features like built-in diodes or resistors?

No, FMMT38CTA is a bare Darlington transistor without integrated base-emitter resistors, clamp diodes, or flyback protection. External components-such as a base resistor for current limiting and a freewheeling diode across inductive loads-are required for reliable operation in typical switching applications.

Can FMMT38CTA replace standard small-signal transistors like MMBT3904 in existing designs?

It can physically fit due to identical SOT23 footprint, but functional substitution requires verification: FMMT38CTA delivers much higher h_FE and V_CE(SAT), so base drive must be reduced (e.g., increase base resistor value), and layout must accommodate higher power dissipation at equivalent currents. Not a direct drop-in replacement without circuit review.

Is the FMMT38CTA marking "7J" sufficient for traceability and authenticity verification?

Yes, "7J" is the official Diodes Incorporated top-marking code for FMMT38CTA per DS40156. Authentic units show laser-etched "7J" on the SOT23 package top surface, aligned with the cathode notch. Traceability is further ensured via Diodes' lot-code system and Aetrix's certified sourcing from authorized channels.

FMMT38CTA 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:: Active

Transistor Type:: NPN - Darlington

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

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 1.25V @ 8mA, 800mA

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 5000 @ 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

FMMT38CTA FAQ

1.How can I place an order for FMMT38CTA through Aetrix?

Please submit a Request for Quotation (RFQ) for FMMT38CTA 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 FMMT38CTA reliable?

The price and inventory of FMMT38CTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMT38CTA is usually 5 days.

3.What payment methods are accepted for FMMT38CTA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMT38CTA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FMMT38CTA?

FMMT38CTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FMMT38CTA 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 FMMT38CTA?

For technical support, including FMMT38CTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMT38CTA requirements.

6.How does Aetrix verify that FMMT38CTA is sourced from the original manufacturer or authorized distributors?

All FMMT38CTA 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 FMMT38CTA meets industry standards.

7.What is the process for return or replacement of FMMT38CTA?

All FMMT38CTA units undergo pre-shipment inspection (PSI). If there is an issue with FMMT38CTA, 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 FMMT38CTA part is unused and in its original packaging.

Return procedure for FMMT38CTA:

1.Submit a request within 90 days.

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

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