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Diodes Incorporated FMMTA42TA
- Part No.:
- FMMTA42TA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
FMMTA42TA.pdf
- Description:
- TRANS NPN 300V 0.2A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,058
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Product details
Overview
FMMTA42TA from Diodes Incorporated is a 300V NPN high-voltage general-purpose transistor in SOT23 package, rated for 200mA collector current and 350mW power dissipation, with minimum hFE of 25 at IC = 1mA/VCE = 10V and BVCEO ≥ 300V. It serves as a high-voltage switching element in offline power supply feedback circuits, LED driver bias stages, and industrial relay drivers.
For engineers reviewing the FMMTA42TA datasheet, FMMTA42TA pinout, FMMTA42TA application, or FMMTA42TA equivalent, key selection criteria include verified 300V VCEO rating, SOT23 thermal resistance (RθJA = 357°C/W on 15mm × 15mm copper), hFE performance up to 30mA, ESD HBM rating of 4kV, and complementary pairing with FMMTA92.
Technical Context
This NPN bipolar junction transistor operates in linear or saturated switching mode with guaranteed breakdown voltage of 300V across both collector-base and collector-emitter terminals. Its fT of 50MHz at VCE = 20V/IC = 10mA supports moderate-speed switching in auxiliary power control loops.
The device exhibits low leakage: ICBO ≤ 100nA at VCB = 200V and ICES ≤ 100nA at VCE = 200V. Saturation parameters are specified under pulsed conditions (≤300µs, ≤2% duty cycle): VCE(sat) ≤ 500mV at IC = 20mA/IB = 2mA and VBE(sat) ≤ 900mV under identical conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 300 V - Enables direct use in 230VAC line-sensing and flyback snubber circuits without external voltage clamping |
| IC | 200 mA - Supports driving small relays, optocoupler LEDs, or gate resistors in <1W auxiliary supplies |
| PD | 350 mW - Achievable on 15mm × 15mm PCB copper; derates to zero at +150°C ambient |
| hFE | 25–40 - Stable DC current gain across 1–30mA range enables predictable base drive sizing |
| fT | 50 MHz - Sufficient for switching frequencies up to ~5MHz in non-critical timing paths |
| ESD HBM | 4000 V - Robust handling during board assembly and rework without additional protection |
| Cobo | 6 pF - Low output capacitance minimizes switching losses in high-impedance collector nodes |
Pinout & Package
Package: SOT23 - Surface-mount plastic package with 0.915mm nominal lead pitch, 2.40mm body length, and UL 94V-0 flammability rating. Moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current sink terminal | Connected to ground or low-side return path; requires low-inductance layout for fast turn-off |
| 2 (Base) | Control input | Driven by resistor-limited voltage source; base current must be sized for target hFE and saturation margin |
| 3 (Collector) | High-voltage output node | Interfaces directly with 300V rails; requires clearance >2.5mm to adjacent traces per IPC-2221B |
Key Features
| Feature | Design Value |
|---|---|
| 300V breakdown rating | Eliminates need for external transient voltage suppressors in 230VAC primary-side sensing |
| Complementary PNP pair (FMMTA92) | Enables matched push-pull configurations in dual-rail interface circuits |
| Lead-free & halogen-free construction | Meets automotive and industrial RoHS 3 and JEDEC J-STD-020 Level 1 requirements out-of-box |
| Matte tin-plated leads | Ensures reliable solder wetting on OSP- and ENIG-finished PCBs without flux optimization |
Applications
| Offline AC-DC Feedback | Industrial Relay Driver |
|---|---|
Use Scenario: Isolating primary-side voltage feedback signal to secondary-side controller via optocoupler. IC Role / Device Role / Timing Role: NPN switch controlling optocoupler LED anode connection to high-voltage rail. Use Value: 300V VCEO withstands reflected flyback spikes; 200mA IC drives standard PC817/PC818 LEDs with margin. | Use Scenario: Driving 12V/24V coil of electromechanical relay from microcontroller GPIO. IC Role / Device Role / Timing Role: Low-side switch sinking relay coil current through emitter. Use Value: 350mW PD accommodates 100ms coil energization pulses; hFE ≥25 ensures <1mA GPIO drive requirement. |
| LED Bias Control | High-Voltage Sensor Interface |
Use Scenario: Providing stable bias current to high-brightness LED strings in signage power supplies. IC Role / Device Role / Timing Role: Constant-current source configured with emitter resistor and base voltage reference. Use Value: Tight hFE distribution (25–40) enables ±15% current regulation without trimming; SOT23 footprint saves space. | Use Scenario: Level-shifting and conditioning signals from 230VAC zero-crossing detectors. IC Role / Device Role / Timing Role: High-impedance input amplifier stage converting AC-derived pulses to logic-compatible levels. Use Value: 6pF Cobo minimizes capacitive coupling noise; 4kV ESD HBM protects against field-induced transients. |
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 | VCEO = 40V, IC = 600mA, fT = 250MHz - lower voltage, higher speed, higher current | Not suitable for >60V collector nodes; requires redesign for 300V operation | Select only when system voltage is ≤40V and faster switching is required |
| ZTX653 | VCEO = 300V, IC = 1A, TO-92 package - same voltage rating but 5× higher current, larger footprint | Requires PCB real estate increase and thermal pad redesign; not drop-in for SOT23 layouts | Choose when >200mA load current or enhanced thermal mass is needed |
Compared with MMBT4401 and ZTX653, FMMTA42TA uniquely balances 300V capability, SOT23 compactness, and 200mA drive in a RoHS 3-compliant package-making it optimal for space-constrained, mains-referenced auxiliary circuits where neither ultra-high speed nor high current dominates.
Availability
FMMTA42TA is available at Aetrix Electronics and suitable for offline AC-DC feedback circuits, industrial relay drivers, and high-voltage sensor interfaces requiring stable component supply across production lifecycles.
Supply support for FMMTA42TA 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 centers across Asia and manufacturing in China, Taiwan, and Malaysia.
FMMTA42TA belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for reliability in mains-connected auxiliary power stages and industrial control interfaces where voltage robustness and RoHS compliance are mandatory.
FAQ
What is the maximum continuous collector current for FMMTA42TA at 70°C ambient?
At TA = 70°C, the maximum continuous collector current is 140mA. This is derived from the 350mW power rating and the derating curve: (150°C − 70°C) × 3.57°C/mW = 286mW remaining dissipation, supporting IC ≈ 140mA at typical VCE(sat) of 0.5V. Operation above this requires forced airflow or thermal vias.
Can FMMTA42TA replace BC846B in a 24V circuit?
No-BC846B has VCEO = 65V and hFE = 200–450, optimized for low-voltage linear amplification. FMMTA42TA's hFE is lower (25–40) and its structure prioritizes 300V breakdown over gain linearity. In a 24V circuit, it functions but wastes board area and increases base drive overhead unnecessarily.
Is the FMMTA42TA marking "3E" decodable to date code or lot information?
No-"3E" is the product type marking code per Diodes' SOT23 labeling standard, identifying the FMMTA42 series. Date codes and lot identifiers are separate and appear elsewhere on the reel label or shipping documentation, not on the device body.
Does FMMTA42TA meet AEC-Q101 for automotive use?
No-only the automotive-qualified variant FMMTA42Q (documented separately) meets AEC-Q101 stress testing. FMMTA42TA is rated for industrial temperature range (−55°C to +150°C) but lacks the qualification test reports, failure analysis protocols, and traceability required for automotive deployment.
FMMTA42TA 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
- 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
FMMTA42TA FAQ
1.How can I place an order for FMMTA42TA through Aetrix?
Please submit a Request for Quotation (RFQ) for FMMTA42TA 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 FMMTA42TA reliable?
The price and inventory of FMMTA42TA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMTA42TA is usually 5 days.
3.What payment methods are accepted for FMMTA42TA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMTA42TA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FMMTA42TA?
FMMTA42TA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FMMTA42TA 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 FMMTA42TA?
For technical support, including FMMTA42TA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMTA42TA requirements.
6.How does Aetrix verify that FMMTA42TA is sourced from the original manufacturer or authorized distributors?
All FMMTA42TA 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 FMMTA42TA meets industry standards.
7.What is the process for return or replacement of FMMTA42TA?
All FMMTA42TA units undergo pre-shipment inspection (PSI). If there is an issue with FMMTA42TA, 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 FMMTA42TA part is unused and in its original packaging.
Return procedure for FMMTA42TA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FMMTA42TA Tags
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MMBT3906LT1G
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MMBT3904-7-F
Diodes Incorporated
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Diodes Incorporated
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BC847B,215
Nexperia USA Inc.
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