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Diodes Incorporated FMMTA42TC
- Part No.:
- FMMTA42TC
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
FMMTA42TC.pdf
- Description:
- TRANS NPN 300V 0.2A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,218
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Product details
Overview
FMMTA42TC from Diodes Incorporated is a 300V NPN high-voltage transistor in SOT23 package, designed for switching and amplification in high-voltage DC-DC converters, relay drivers, and snubber circuits. It delivers 200mA collector current, 350mW power dissipation, and exhibits hFE ≥25 at IC = 1mA with VCE = 10V - enabling stable gain control in low-power industrial controls.
For engineers reviewing the FMMTA42TC datasheet, FMMTA42TC pinout, FMMTA42TC application, or FMMTA42TC equivalent, key selection criteria include its 300V BVCEO, 500mV VCE(sat) at IC = 20mA/IB = 2mA, 6pF Cobo at 20V, 50MHz fT, and SOT23 thermal resistance of 357°C/W (on 15mm × 15mm copper).
Technical Context
This NPN bipolar junction transistor operates with a minimum breakdown voltage of 300V across both collector-base and collector-emitter terminals, supporting high-side switching in off-line auxiliary supplies. Its 7V VEBO rating and 100nA ICBO at VCB = 200V ensure reliable blocking under transient overvoltage conditions.
The device achieves 50MHz transition frequency at VCE = 20V and IC = 10mA, indicating usable RF capability up to low-VHF range. Its hFE maintains ≥25–40 across IC = 1–30mA, supporting consistent current gain in linear and saturated switching modes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| BVCEO | 300 V - Enables direct use in 230V AC rectified bus switching without external clamping |
| IC | 200 mA - Supports driving small relays, optocouplers, or gate resistors in HV MOSFET bias networks |
| PD | 350 mW - Allows continuous operation at 200mA with ≤1.75V VCE in ambient ≤70°C on standard PCB layout |
| hFE | 25–40 - Ensures predictable base drive requirements for saturation in discrete switch designs |
| VCE(sat) | 500 mV @ IC=20mA, IB=2mA - Minimizes conduction loss and self-heating in pulsed switching applications |
| fT | 50 MHz - Supports stable amplification or oscillation in low-noise signal conditioning stages up to 10MHz |
| Cobo | 6 pF @ VCB=20V - Limits Miller capacitance-induced delay in fast turn-off scenarios |
Pinout & Package
Package: SOT23 - Surface-mount plastic package with 0.008g mass, UL 94V-0 flammability rating, and matte tin-plated leads compliant with MIL-STD-202 Method 208 solderability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current sink terminal | Connected to ground or low-side return path; defines reference for VBE and VCE measurements |
| 2 (Base) | Control input | Receives current-limited drive to bias transistor into active or saturation region; requires series resistor for current limiting |
| 3 (Collector) | High-voltage output node | Switches loads referenced to high-voltage rail (up to 300V); connects to snubber networks or flyback diode anodes |
Key Features
| Feature | Design Value |
|---|---|
| 300V breakdown rating | Eliminates need for external voltage clamping in 230VAC-derived auxiliary supplies |
| Complementary PNP pair (FMMTA92) | Enables matched push-pull or differential amplifier topologies without cross-manufacturer sourcing |
| Lead-free & halogen-free "Green" construction | Meets RoHS 3 (2015/863/EU) and automotive ELV directive requirements without process requalification |
| ESD HBM rating of 4kV | Reduces handling sensitivity during manual assembly and board-level testing in non-ESD-controlled environments |
| Thermal resistance RθJL = 350°C/W | Supports higher pulse current capability via lead-to-PCB heat transfer, critical for intermittent relay coil driving |
Applications
| Industrial Relay Drivers | Off-Line Auxiliary Power Supplies |
|---|---|
Use Scenario: Driving 12V/24V electromagnetic relays from microcontroller GPIO in programmable logic controllers. IC Role / Device Role / Timing Role: High-voltage NPN switch controlling relay coil current with 300V standoff margin against inductive kickback. Use Value: Eliminates need for TVS clamping diodes due to intrinsic 300V BVCEO, reducing BOM count and PCB area. | Use Scenario: Regulating auxiliary 12V supply from rectified 230VAC mains in AC-DC SMPS feedback circuitry. IC Role / Device Role / Timing Role: Linear pass transistor or error amplifier driver in shunt-regulated auxiliary winding feedback loop. Use Value: Stable hFE across 1–30mA enables precise current mirroring for optocoupler LED biasing without trimming. |
| Snubber Networks | High-Voltage Signal Level Shifting |
Use Scenario: Active snubbing of flyback transformer leakage spikes in low-cost flyback converters. IC Role / Device Role / Timing Role: Fast-turnoff NPN clamp activated by voltage-sense network to absorb energy during MOSFET turn-off. Use Value: 6pF Cobo minimizes capacitive loading on sense node, preserving timing accuracy of snubber trigger. | Use Scenario: Translating logic-level signals to 100–300V domains for gate driving or status monitoring in HV inverters. IC Role / Device Role / Timing Role: Level-shifting buffer isolating MCU outputs from high-side floating potentials using open-collector configuration. Use Value: 500mV VCE(sat) ensures minimal voltage drop when sinking level-shifted signals, improving noise margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage NPN transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBT4401 | BVCEO = 40V, IC = 600mA, fT = 250MHz - lower voltage rating, higher speed and current | Suitable only for sub-60V systems; cannot replace FMMTA42TC in 230VAC-derived circuits | Select only where voltage stress <40V and higher fT is required for signal amplification |
| ZTX653 | BVCEO = 300V, IC = 1A, SOT89 package - same voltage rating but higher current and larger footprint | Requires PCB redesign due to SOT89 thermal pad and 4.5mm × 2.5mm outline vs. SOT23's 2.9mm × 1.3mm | Choose when >200mA load current or enhanced thermal performance is needed, accepting larger board area |
Compared with MMBT4401 and ZTX653, FMMTA42TC uniquely balances 300V standoff, SOT23 compactness, and 200mA capability - making it optimal for space-constrained, high-input-voltage auxiliary functions where neither low-voltage speed nor high-current thermal mass is primary.
Availability
FMMTA42TC is available at Aetrix Electronics and suitable for industrial relay drivers, off-line auxiliary power supplies, snubber networks, and high-voltage signal level shifting requiring stable component supply and long-term manufacturability.
Supply support for FMMTA42TC 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, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.
The FMMTA42TC belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for cost-sensitive, space-constrained industrial and consumer power management applications demanding robust 300V operation in miniature packages.
FAQ
What is the maximum continuous collector current for FMMTA42TC at 100°C ambient temperature?
At TA = 100°C, the maximum continuous collector current is derated to approximately 120mA based on the published derating curve (Figure 1), assuming mounting on 15mm × 15mm 1oz copper. This reflects thermal limitation rather than electrical failure, and operation above this requires forced cooling or reduced duty cycle.
Can FMMTA42TC be used in avalanche mode?
No - FMMTA42TC is not rated or characterized for controlled avalanche operation. Its absolute maximum ratings specify only steady-state and pulsed safe operating area (Figure 4), and no avalanche energy (EAS) or ruggedness data is provided in the datasheet. Intentional avalanche use may cause parametric shift or catastrophic failure.
Is the FMMTA42TC pinout compatible with standard SOT23 NPN transistors like BC846 or MMBT3904?
Yes - FMMTA42TC uses standard SOT23 pinout (Emitter-Base-Collector on pins 1-2-3), matching BC846, MMBT3904, and most JEDEC-compliant SOT23 NPN transistors. However, electrical differences - especially 300V BVCEO versus 65V for BC846 - mean direct substitution requires verification of voltage stress margins in the target circuit.
Does FMMTA42TC meet AEC-Q101 for automotive use?
No - the standard FMMTA42TC is not AEC-Q101 qualified. Diodes offers the automotive-grade variant FMMTA42Q, which undergoes additional stress testing per AEC-Q101 and is documented in a separate datasheet (DS33126Q). Use of FMMTA42TC in automotive applications requires full qualification by the end customer.
FMMTA42TC 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):
- 200 mA
- Voltage - Collector Emitter Breakdown (Max):
- 300 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 2mA, 20mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 40 @ 30mA, 10V
- Power - Max:
- 330 mW
- Frequency - Transition:
- 50MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
FMMTA42TC FAQ
1.How can I place an order for FMMTA42TC through Aetrix?
Please submit a Request for Quotation (RFQ) for FMMTA42TC 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 FMMTA42TC reliable?
The price and inventory of FMMTA42TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMTA42TC is usually 5 days.
3.What payment methods are accepted for FMMTA42TC?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMTA42TC transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FMMTA42TC?
FMMTA42TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FMMTA42TC 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 FMMTA42TC?
For technical support, including FMMTA42TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMTA42TC requirements.
6.How does Aetrix verify that FMMTA42TC is sourced from the original manufacturer or authorized distributors?
All FMMTA42TC 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 FMMTA42TC meets industry standards.
7.What is the process for return or replacement of FMMTA42TC?
All FMMTA42TC units undergo pre-shipment inspection (PSI). If there is an issue with FMMTA42TC, 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 FMMTA42TC part is unused and in its original packaging.
Return procedure for FMMTA42TC:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FMMTA42TC Tags
-
MMBT3906LT1G
onsemi
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MMBT3904-7-F
Diodes Incorporated
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MMBT3904LT1G
onsemi
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MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
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MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
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BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
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