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

Diodes Incorporated FMMT551TC

Name: FMMT551TC
Brand: Diodes Incorporated
SKU: FMMT551TC
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FMMT551TC

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

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

Datasheet:: FMMT551TC.pdf

Description:: TRANS PNP 60V 1A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Inventory:6,579

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Product details

Overview

FMMT551TC from Diodes Incorporated is a PNP silicon planar medium-power transistor in SOT-23 package, rated for -60 V V_CEO, -1 A continuous collector current, and 500 mW power dissipation at 25°C ambient. It delivers h_FE of 50–150 at -150 mA / -10 V and operates up to 150 MHz f_T, commonly used in low-voltage DC-DC converter switching stages and load-switching circuits.

For engineers reviewing the FMMT551TC datasheet, FMMT551TC pinout, FMMT551TC application, or FMMT551TC equivalent, key selection criteria include verified V_CEO(-60 V), I_C(-1 A), h_FE range at two bias points, V_CE(sat)(-0.35 V @ -150 mA/-15 mA), and SOT-23 thermal derating behavior under pulsed operation.

Technical Context

This PNP bipolar junction transistor uses planar epitaxial construction to support medium-power linear and switching functions with defined safe operating area (SOA) limits up to 100 V and 1 A under pulsed conditions (300 µs, ≤2% duty cycle). Its complementary pairing with FMMT451 enables push-pull and H-bridge topologies.

Electrical characterization includes guaranteed V_(BR)CBO (-80 V), V_CEO(sus) (-60 V), and V_BE(sat) (-1.1 V @ -150 mA/-15 mA), with f_T measured at -50 mA/-10 V and 100 MHz. Output capacitance C_obo is specified at -10 V V_CB.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-60 V - Maximum sustainable collector-emitter voltage before breakdown in common-emitter configuration.
I_C (continuous)	-1 A - Continuous DC collector current rating at T_amb = 25°C; derates above 25°C per thermal resistance.
P_tot	500 mW - Total power dissipation limit at 25°C ambient; requires heatsinking or derating for sustained operation.
h_FE	50–150 - DC current gain range across two test conditions: -150 mA/-10 V and -1 A/-10 V.
f_T	150 MHz - Transition frequency at -50 mA/-10 V, indicating usable bandwidth for medium-speed switching.
V_CE(sat)	-0.35 V @ -150 mA/-15 mA - Low saturation voltage enables efficient switching in low-voltage load control.

Pinout & Package

Supplied in SOT-23 surface-mount package with standard pin assignment: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Emitter)	Current exit node for PNP device	Connected to higher potential rail in high-side switch configurations; referenced for base drive.
Pin 2 (Base)	Control terminal for minority-carrier injection	Requires negative current relative to emitter to turn on; IB ≤ -200 mA absolute max.
Pin 3 (Collector)	Main current input node	Connected to load return path; withstands -60 V reverse bias in active switching.

Key Features

Feature	Design Value
Medium-power PNP switching capability	Rated for -1 A continuous and -2 A pulsed collector current with defined SOA curves.
Low V_CE(sat) at moderate current	-0.35 V at -150 mA/-15 mA enables <100 mW conduction loss in 5 V systems.
High f_T bandwidth	150 MHz transition frequency supports PWM switching up to ~10–20 MHz with acceptable gain margin.
Complementary pairing	Matched performance with FMMT451 (NPN) for balanced push-pull and bridge driver designs.

Applications

DC-DC Converter Switching Stage

Industrial Load Switch

Use Scenario: Used as synchronous rectifier or high-side switch in non-isolated buck converters operating at 3–12 V input.

IC Role / Device Role / Timing Role: PNP transistor configured as saturated switch controlling current flow from supply rail to inductor/load.

Use Value: V_CE(sat) ≤ -0.35 V minimizes conduction loss; SOA compliance ensures reliability under transient overloads.

Use Scenario: Controls 24 V solenoid or relay coil in programmable logic controller (PLC) output modules.

IC Role / Device Role / Timing Role: High-side load switch driven by microcontroller GPIO through base resistor network.

Use Value: -60 V V_CEO provides margin against inductive kickback; -1 A rating covers typical 500 mA solenoid loads.

LED Driver Current Sink

Signal-Level Level Shifter

Use Scenario: Sinks current from multi-segment LED arrays in automotive interior lighting with 5–24 V supply rails.

IC Role / Device Role / Timing Role: Acts as constant-current sink controlled via PWM base drive.

Use Value: h_FE stability across -150 mA to -1 A enables predictable current regulation without external feedback.

Use Scenario: Translates 3.3 V logic signals to -5 V or -12 V domains in mixed-supply interface circuits.

IC Role / Device Role / Timing Role: Inverted level shifter using common-emitter configuration with pull-up to negative rail.

Use Value: V_BE(sat) of -1.1 V ensures clean logic thresholds; f_T > 100 MHz supports >10 Mbps data rates.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP medium-power switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ZTX653	V_CEO = -60 V, I_C = -1 A, but h_FE min = 100 @ -500 mA; SOT-89 package.	Larger footprint and higher thermal mass; better suited for continuous 500 mA+ loads.	Select when board space allows SOT-89 and higher h_FE consistency is required at mid-current.
MMBT5551	NPN complement (not PNP); V_CEO = 160 V, I_C = 600 mA - not functionally interchangeable.	Only suitable in NPN-configured circuits; cannot replace FMMT551TC in high-side or complementary roles.	Not a direct alternative; consider only if redesigning topology to use NPN high-side drive with level-shifting.

Compared with ZTX653, FMMT551TC offers smaller SOT-23 footprint and lower V_CE(sat) at light loads but reduced h_FE minimum at 1 A; versus MMBT5551, it provides true PNP functionality essential for high-side switching without gate-drive complexity.

Availability

FMMT551TC is available at Aetrix Electronics and suitable for industrial PLC output modules, automotive interior LED drivers, and 5–24 V DC-DC converter switching stages requiring stable component supply and traceable sourcing.

Supply support for FMMT551TC 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 and manufacturing operations across Asia and the Americas.

FMMT551TC belongs to the FMMT series of medium-power transistors engineered for reliable switching and amplification in space-constrained industrial and automotive applications where SOT-23 footprint and defined SOA are critical.

FAQ

What is the maximum safe pulsed collector current for FMMT551TC?

The absolute maximum pulsed collector current is -2 A, tested under pulsed conditions (pulse width = 300 µs, duty cycle ≤ 2%). Operation beyond this requires verification against the published Safe Operating Area curve, especially at elevated V_CE and ambient temperature.

Does FMMT551TC support linear (analog) amplification applications?

Yes - its h_FE range (50–150) and f_T of 150 MHz support low-noise, medium-gain linear amplification at frequencies up to ~10 MHz. However, thermal limitations in SOT-23 require careful biasing and heat management for sustained analog use.

How does FMMT551TC's V_BE(sat) affect base drive requirements?

V_BE(sat) is -1.1 V at -150 mA collector current and -15 mA base current. This defines minimum base-emitter forward voltage needed for saturation; base resistors must be sized to deliver ≥15 mA while accounting for MCU GPIO voltage drop and temperature drift.

Is FMMT551TC RoHS compliant and halogen-free?

Yes - Diodes Incorporated certifies FMMT551TC as RoHS compliant and halogen-free per their standard product specifications (document number DIO-000017). Full compliance documentation is available upon request with lot traceability.

FMMT551TC 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:: PNP

Current - Collector (Ic) (Max):: 1 A

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

Vce Saturation (Max) @ Ib, Ic:: 350mV @ 15mA, 150mA

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 50 @ 150mA, 10V

Power - Max:: 500 mW

Frequency - Transition:: 150MHz

Operating Temperature:: -55°C ~ 200°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

FMMT551TC FAQ

1.How can I place an order for FMMT551TC through Aetrix?

Please submit a Request for Quotation (RFQ) for FMMT551TC 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 FMMT551TC reliable?

The price and inventory of FMMT551TC are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FMMT551TC is usually 5 days.

3.What payment methods are accepted for FMMT551TC?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FMMT551TC transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FMMT551TC?

FMMT551TC orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FMMT551TC 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 FMMT551TC?

For technical support, including FMMT551TC datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FMMT551TC requirements.

6.How does Aetrix verify that FMMT551TC is sourced from the original manufacturer or authorized distributors?

All FMMT551TC 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 FMMT551TC meets industry standards.

7.What is the process for return or replacement of FMMT551TC?

All FMMT551TC units undergo pre-shipment inspection (PSI). If there is an issue with FMMT551TC, 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 FMMT551TC part is unused and in its original packaging.

Return procedure for FMMT551TC:

1.Submit a request within 90 days.

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

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