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Diodes Incorporated FMMT549TA
- Part No.:
- FMMT549TA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
FMMT549TA.pdf
- Description:
- TRANS PNP 30V 1A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,472
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Product details
Overview
FMMT549TA from Diodes Incorporated is a 30V PNP silicon planar high-voltage transistor in SOT23 package, rated for -1A continuous collector current, -30V VCEO, and 500mW power dissipation. It serves as a general-purpose switching or linear amplification device in automotive power management, industrial sensor interfaces, and DC-DC converter bias circuits.
For engineers reviewing the FMMT549TA datasheet, FMMT549TA pinout, FMMT549TA application, or FMMT549TA equivalent, key selection criteria include its AEC-Q101 qualification, -30V breakdown rating, hFE range of 70–200 at -50mA/-2V, VCE(sat) ≤ -500mV at -1A/-100mA, and thermal resistance of 250°C/W in standard FR4 layout.
Technical Context
This PNP bipolar junction transistor operates with emitter-grounded configuration and supports pulsed and DC switching up to 2A peak. Its BVCEO = -30V and BVCBO = -35V enable use in higher-voltage rail monitoring and load-switching applications where reverse polarity protection or high-side switch control is required.
The device delivers hFE = 150–200 (FMMT549A variant) at -500mA/-2V, with fT = 100MHz and Cobo = 25pF, supporting medium-speed switching (ton = 50ns, toff = 300ns) in compact power stages without requiring external base drive compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -30V - Maximum safe collector-emitter voltage under open-base condition; defines upper rail limit in high-side switch designs |
| IC (cont.) | -1A - Continuous DC collector current capability; determines maximum load drive in relay drivers or LED current sinks |
| PD | 500mW - Power dissipation on FR4 PCB with minimum copper; sets thermal derating boundary at ambient temperatures above 25°C |
| hFE | 70–200 - DC current gain at -50mA/-2V; enables predictable base resistor sizing for saturated switching |
| VCE(sat) | ≤ -500mV @ -1A/-100mA - Low saturation voltage reduces conduction loss in power path applications |
| fT | 100MHz - Transition frequency confirms suitability for sub-100ns switching in SMPS feedback or signal routing |
| RθJA | 250°C/W - Junction-to-ambient thermal resistance under JEDEC-standard board layout; informs heatsinking requirements |
Pinout & Package
Package: SOT23 - Surface-mount plastic case, UL 94V-0 rated, 0.008g weight, matte tin terminals solderable per MIL-STD-202.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current source terminal | Connected to positive supply in high-side switch; must handle full load current and withstand reverse voltage transients |
| 2 (Base) | Control input | Receives current-limited drive; requires series resistor to limit IB ≤ -200mA and ensure saturation at target IC |
| 3 (Collector) | Current sink terminal | Connected to load; voltage swing limited by VCEO and VCBO; primary path for heat generation during conduction |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per stress test conditions |
| Lead-free & halogen-free | Complies with RoHS Directive 2011/65/EU and Diodes Inc.'s "Green" policy; no antimony or brominated flame retardants |
| Moisture Sensitivity Level 1 | Unlimited floor life at ≤30°C/60% RH; no baking required prior to reflow soldering |
| UL 94V-0 flammability rating | Self-extinguishing plastic housing meets safety standards for enclosed industrial and automotive enclosures |
Applications
| Automotive Body Control Module | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Driving resistive loads such as door lock actuators or HVAC damper motors in 12V/24V vehicle systems. IC Role / Device Role / Timing Role: High-side PNP switch controlling current flow from battery rail to grounded load. Use Value: -30V VCEO accommodates load-dump transients up to 28V; AEC-Q101 qualification ensures operation across -40°C to +125°C ambient. | Use Scenario: Level-shifting and current amplification for analog output sensors feeding microcontroller ADC inputs. IC Role / Device Role / Timing Role: Linear amplifier configured in common-emitter mode to boost weak sensor currents while maintaining DC coupling. Use Value: hFE ≥ 70 at -50mA ensures stable gain over temperature; low VCE(sat) minimizes offset error in precision current mirrors. |
| DC-DC Converter Bias Circuit | LED Current Sink Driver |
Use Scenario: Providing regulated base drive to main power MOSFETs in isolated flyback or forward converters. IC Role / Device Role / Timing Role: Fast-switching PNP transistor enabling precise timing control of gate driver turn-on/turn-off edges. Use Value: ton = 50ns and toff = 300ns support >1MHz switching frequencies; fT = 100MHz ensures minimal phase lag in feedback paths. | Use Scenario: Constant-current sinking for high-brightness indicator LEDs in panel displays or status lighting. IC Role / Device Role / Timing Role: Linear current regulator using emitter degeneration resistor and fixed base bias. Use Value: 500mW power rating allows sustained -1A operation with proper PCB copper area; VBE(on) = -850mV enables accurate current setpoint with low-tolerance resistors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP high-voltage switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZXTN25050DFH | VCEO = -50V, IC = -1.5A, SOT23 package, hFE = 100–300 at -500mA | Higher voltage margin and gain; suitable for 48V industrial systems | Select when >30V breakdown headroom or tighter hFE tolerance is required |
| MMBT5401 | VCEO = -60V, IC = -0.6A, SOT23, hFE = 60–250 at -10mA | Lower current rating but wider gain spread; optimized for low-power signal switching | Prefer for low-IC (<500mA), high-VCEO applications where thermal load is minimal |
Compared with ZXTN25050DFH and MMBT5401, FMMT549TA offers balanced performance at -30V/1A with AEC-Q101 validation-making it optimal for cost-sensitive, thermally constrained automotive and industrial switching where exact 30V rail compatibility and automotive qualification are mandatory.
Availability
FMMT549TA is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, and DC-DC converter bias circuits requiring stable component supply and long-term production continuity.
Supply support for FMMT549TA 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 computing markets.
The FMMT series targets high-voltage, high-speed bipolar transistors for power switching and signal conditioning in space-constrained, thermally demanding environments.
FAQ
What is the difference between FMMT549TA and FMMT549ATA?
FMMT549TA corresponds to the standard FMMT549 variant with hFE = 70–200 at -50mA/-2V, while FMMT549ATA is the FMMT549A version offering higher gain (hFE = 150–200 at -500mA/-2V) and improved VCE(sat) (-300mV at -100mA/-1mA). Both share identical SOT23 pinout and voltage ratings.
Is FMMT549TA suitable for linear amplification?
Yes-its specified hFE range, low VCE(sat), and fT = 100MHz support stable common-emitter amplification at DC and low RF frequencies. Designers must ensure thermal derating below 500mW and maintain VCE > 1V to avoid saturation distortion in analog gain stages.
Does FMMT549TA require a heatsink in typical SOT23 mounting?
No-under standard JEDEC FR4 layout with 1 oz copper, RθJA = 250°C/W allows full 500mW dissipation up to +75°C ambient. For continuous 1A operation near maximum temperature, increase local copper area or add thermal vias; no external heatsink is needed in most applications.
Can FMMT549TA replace BC807 in existing designs?
Only with verification: BC807 has VCEO = -45V and IC = -500mA, whereas FMMT549TA offers higher current (-1A) but lower voltage (-30V). If the original design operates below 25V and demands >500mA, FMMT549TA improves performance; if >30V rail transients occur, it risks breakdown and is not a drop-in replacement.
FMMT549TA 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:
- PNP
- Current - Collector (Ic) (Max):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 30 V
- Vce Saturation (Max) @ Ib, Ic:
- 750mV @ 200mA, 2A
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 100 @ 500mA, 2V
- Power - Max:
- 500 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
FMMT549TA FAQ
1.How can I place an order for FMMT549TA through Aetrix?
Please submit a Request for Quotation (RFQ) for FMMT549TA 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 FMMT549TA reliable?
The price and inventory of FMMT549TA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMT549TA is usually 5 days.
3.What payment methods are accepted for FMMT549TA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMT549TA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FMMT549TA?
FMMT549TA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FMMT549TA 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 FMMT549TA?
For technical support, including FMMT549TA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMT549TA requirements.
6.How does Aetrix verify that FMMT549TA is sourced from the original manufacturer or authorized distributors?
All FMMT549TA 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 FMMT549TA meets industry standards.
7.What is the process for return or replacement of FMMT549TA?
All FMMT549TA units undergo pre-shipment inspection (PSI). If there is an issue with FMMT549TA, 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 FMMT549TA part is unused and in its original packaging.
Return procedure for FMMT549TA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
FMMT549TA Tags
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