My Inquiry
My Account
Diodes Incorporated FMMT459QTA
- Part No.:
- FMMT459QTA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
FMMT459QTA.pdf
- Description:
- TRANS NPN 450V 0.15A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:10,617
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
FMMT459QTA from Diodes Incorporated is a 500V NPN high-voltage bipolar junction transistor (BJT) in SOT23 package, designed for automotive-grade off-line switching and PFC disable functions. It delivers 150mA continuous collector current, 500V VCEV breakdown, and low 60mV VCE(sat) at 20mA/2mA drive - enabling reliable high-voltage switching in emergency lighting and telecom protected line circuits.
For engineers reviewing the FMMT459QTA datasheet, FMMT459QTA pinout, FMMT459QTA application, or FMMT459QTA equivalent, key selection criteria include its AEC-Q101 qualification, 625mW power dissipation at TA=25°C, reverse blocking capability (VECV = 6V), and hFE range of 50–120 at 30–50mA - all critical for high-reliability HV switching designs.
Technical Context
This NPN BJT operates with a minimum BVCEV of 500V and BVCEO of 450V, supporting high-voltage isolation in RCD snubbers and PFC disable paths. Its 7V VEBO and 6V reverse-blocking VECV enable bidirectional control in piezo actuator drivers and telecom line protection circuits.
The device features 50–120 DC current gain (hFE) across 30–50mA IC, with VCE(sat) ≤ 60mV at IC/IB = 10, ensuring efficient conduction under pulsed loads up to 500mA ICM. Thermal resistance RθJA is 200°C/W on FR4 (25mm × 25mm 1oz Cu), defining safe operating area limits for sustained 150mA operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEV | 500 V - Enables use as high-side switch in 400V DC bus applications without avalanche stress |
| IC (continuous) | 150 mA - Supports steady-state current in PFC disable and emergency lighting control paths |
| VCE(sat) | 60 mV @ 20mA/2mA - Minimizes conduction loss and self-heating during active switching |
| hFE | 50–120 @ 30–50mA - Ensures stable base drive design margin across temperature and production lot variation |
| PD | 625 mW @ TA = 25°C - Defines maximum ambient-operated power before thermal derating begins |
| toff | 3450 ns - Determines minimum switching frequency limit in RCD clamp and flyback auxiliary circuits |
| ESD HBM | 4000 V - Meets automotive ESD robustness requirements for board-level handling and integration |
Pinout & Package
Package: SOT23 - surface-mount plastic package with matte tin-plated leads, UL 94V-0 rated molding compound, and 0.008g mass. Moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current sink terminal | Connected to ground or return path; supports reverse-blocking up to 6V (VECV) |
| 2 (Base) | Control input | Drives transistor into saturation with 2–6mA; VBE(sat) ≤ 0.9V ensures TTL/CMOS compatibility |
| 3 (Collector) | High-voltage output node | Rated for 500V VCB; connects to primary-side HV rail in offline SMPS and telecom line switches |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive temperature range (−55°C to +150°C) and mechanical stress testing |
| 500V VCEV rating | Enables direct replacement of legacy 400V transistors in upgraded HV designs without layout change |
| Low 60mV VCE(sat) | Reduces power loss by >30% vs. comparable 100mV-saturation devices at 20mA load |
| Green, halogen-free construction | Complies with IPC-1752A material declaration requirements for RoHS 2 and ELV directives |
| PPAP capable | Supports full production part approval process documentation for Tier-1 automotive suppliers |
Applications
| Automotive Off-Line Switching | PFC Disable Function |
|---|---|
Use Scenario: High-voltage switching in engine control unit (ECU) auxiliary power supplies and body electronics modules. IC Role / Device Role / Timing Role: NPN high-side switch controlling 400V DC bus discharge during fault conditions. Use Value: 500V VCEV prevents breakdown during transient overvoltage events common in 12V/24V vehicle systems. |
Use Scenario: Enabling/disabling Power Factor Correction circuitry in AC-DC adapters for industrial equipment. IC Role / Device Role / Timing Role: Low-power control switch isolating PFC controller bias supply upon overtemperature detection. Use Value: 150mA IC and 625mW PD support continuous duty-cycle operation without heatsinking. |
| Telecom Line Protection | Piezo Actuator Driver |
Use Scenario: Overvoltage clamping and surge routing in analog telephone line interface cards (LICs). IC Role / Device Role / Timing Role: Fast-turn-off switch in RCD snubber networks protecting line transceivers from lightning-induced transients. Use Value: 3450ns toff enables precise timing control in sub-microsecond transient suppression cycles. |
Use Scenario: Driving high-impedance piezoelectric elements in automotive fuel injectors and precision positioning stages. IC Role / Device Role / Timing Role: Voltage-controlled current source delivering fast rise/fall pulses to piezo stacks. Use Value: 6V VECV reverse blocking allows bidirectional voltage swing without external diode protection. |
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 |
|---|---|---|---|
| ZXTN25012E6TA | 400V VCEO, 200mA IC, SOT23-6 package with emitter-connected base resistor | Lacks AEC-Q101 qualification; suited for industrial but not automotive deployment | Select when integrated base resistor simplifies drive circuitry and 400V rating suffices |
| MMBT4401-7-F | 40V VCEO, 600mA IC, same SOT23 footprint but lower voltage rating | Not suitable for off-line or telecom HV applications; limited to low-voltage logic-level switching | Choose only for cost-sensitive, non-HV designs where 40V ceiling is acceptable |
Compared with ZXTN25012E6TA and MMBT4401-7-F, FMMT459QTA uniquely combines automotive qualification, 500V breakdown, and SOT23 form factor - making it the sole option for space-constrained, safety-critical HV switching where both reliability and voltage headroom are mandatory.
Availability
FMMT459QTA is available at Aetrix Electronics and suitable for automotive ECUs, telecom line interface cards, and emergency lighting controllers requiring stable component supply across extended product lifecycles.
Supply support for FMMT459QTA 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 North America.
FMMT459QTA belongs to Diodes' Automotive-Grade High-Voltage Transistor product line, engineered specifically for AEC-Q101-compliant off-line switching, PFC control, and telecom protection - prioritizing voltage robustness and thermal stability in harsh environments.
FAQ
What is the maximum allowable collector-emitter voltage for continuous operation?
The FMMT459QTA has a VCEO rating of 450V - this is the maximum DC voltage that can be continuously applied between collector and emitter with base open. Exceeding this value risks permanent breakdown, even if VCEV is rated at 500V under pulsed, reverse-biased base conditions.
Can FMMT459QTA replace FMMT458QTA in existing designs?
Yes - FMMT459QTA and FMMT458QTA share identical SOT23 packaging, pinout, and thermal characteristics, but FMMT459QTA offers higher 500V VCEV versus 400V for the 458 variant. No layout or drive circuit changes are needed, though system-level overvoltage margin improves.
Is the device suitable for linear amplifier applications?
No - FMMT459QTA is optimized for switching operation, not linear amplification. Its hFE variation across IC (50–120) and lack of specified fT linearity make it unsuitable for analog gain stages; it is intended for saturated-switch or pulse-control roles only.
What is the recommended PCB pad layout for thermal performance?
Use the SOT23 pad layout defined in Diodes' AP02001 document: 0.9mm × 0.9mm pads for pins 1 and 2, 0.9mm × 1.35mm for pin 3 (collector), with 0.2mm solder mask clearance. Connect the collector pad to ≥25mm² 1oz copper pour to achieve the 200°C/W RθJA rating.
FMMT459QTA 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):
- 150 mA
- Voltage - Collector Emitter Breakdown (Max):
- 450 V
- Vce Saturation (Max) @ Ib, Ic:
- 90mV @ 6mA, 50mA
- Current - Collector Cutoff (Max):
- 100nA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 50 @ 30mA, 10V
- Power - Max:
- 806 mW
- Frequency - Transition:
- 50MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
FMMT459QTA FAQ
1.How can I place an order for FMMT459QTA through Aetrix?
Please submit a Request for Quotation (RFQ) for FMMT459QTA 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 FMMT459QTA reliable?
The price and inventory of FMMT459QTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMT459QTA is usually 5 days.
3.What payment methods are accepted for FMMT459QTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMT459QTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FMMT459QTA?
FMMT459QTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FMMT459QTA 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 FMMT459QTA?
For technical support, including FMMT459QTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMT459QTA requirements.
6.How does Aetrix verify that FMMT459QTA is sourced from the original manufacturer or authorized distributors?
All FMMT459QTA 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 FMMT459QTA meets industry standards.
7.What is the process for return or replacement of FMMT459QTA?
All FMMT459QTA units undergo pre-shipment inspection (PSI). If there is an issue with FMMT459QTA, 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 FMMT459QTA part is unused and in its original packaging.
Return procedure for FMMT459QTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FMMT459QTA Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
