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

onsemi BD1366STU

Name: BD1366STU
Brand: onsemi
SKU: BD1366STU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BD1366STU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-225AA, TO-126-3

Datasheet:: BD1366STU.pdf

Description:: TRANS PNP 45V 1.5A TO-126-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BD1366STU from Fairchild Semiconductor is a PNP epitaxial silicon transistor in TO-126 package, rated for -45 V V_CEO, -1.5 A continuous collector current, and 12.5 W collector dissipation at T_C=25°C, used in medium-power linear amplification and switching applications such as audio output stages and relay drivers.

For engineers reviewing the BD1366STU datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_CEO/V_CBO ratings, h_FE classification bands (40–100), V_CE(sat) ≤ -0.5 V at I_C = -500 mA/I_B = -50 mA, thermal derating behavior, and TO-126 mechanical compatibility with heatsink mounting.

Technical Context

This PNP bipolar junction transistor operates in active, saturation, and cutoff regions with DC current gain (h_FE) specified across three test conditions: 25–250 at I_C = -5 mA, -0.5 A, and -150 mA respectively. Its safe operating area (SOA) is defined for pulsed (10 µs–DC) and continuous operation, with power derating linear above 25°C case temperature.

V_CE(sat) and V_BE(on) are characterized under controlled bias conditions (-2 V V_CE, -0.5 A I_C), and leakage currents (I_CBO ≤ -0.1 µA, I_EBO ≤ -10 µA) confirm low off-state conduction. The device is explicitly designated for medium-power linear and switching use, not RF or high-speed switching.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-45 V - Maximum allowable collector-emitter voltage before breakdown in common-emitter configuration
I_C (DC)	-1.5 A - Continuous collector current limit defining steady-state power handling capability
P_C (T_C=25°C)	12.5 W - Maximum dissipated power with case temperature held at 25°C; requires heatsink
h_FE (I_C=-150 mA)	40–100 - DC current gain range used to size base drive for switching saturation or linear bias stability
V_CE(sat)	-0.5 V @ I_C=-500 mA, I_B=-50 mA - Confirmed low-saturation voltage enabling efficient switching with minimal conduction loss
T_J	150°C - Maximum junction temperature determining thermal design margin and reliability lifetime
V_EBO	-5 V - Emitter-base reverse voltage limit preventing emitter junction avalanche during turn-off transients

Pinout & Package

BD1366STU is housed in a TO-126 plastic package with integral metal tab for heatsink mounting. Pin 1 is Emitter, Pin 2 is Collector (connected to tab), Pin 3 is Base - confirmed by Fairchild's official package drawing and pin identification note.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit node in PNP operation	Connected to higher-potential rail in switching configurations; referenced for base bias network
2 (Collector)	Current entry node; electrically tied to metal tab	Must be isolated from chassis unless circuit ground is collector reference; primary thermal path to heatsink
3 (Base)	Control terminal for minority-carrier injection	Requires current-limited drive (≤ -0.5 A) to avoid damage; sensitive to ESD per JEDEC JESD22-A114

Key Features

Feature	Design Value
TO-126 power package	Enables direct bolt-on heatsinking with 12.5 W dissipation at T_C=25°C and defined thermal resistance (R_θJC ≈ 2.0°C/W)
h_FE classification band	Guaranteed 40–100 at I_C=-150 mA supports predictable base drive design without margin overdesign
V_CE(sat) ≤ -0.5 V	Reduces conduction loss in saturated switching, critical for efficiency in relay and lamp driver circuits
Low I_CBO (≤ -0.1 µA)	Ensures stable off-state behavior in high-impedance bias networks and temperature-varying environments
Complementary pairing	Designed as PNP counterpart to BD135 (NPN), enabling push-pull amplifier and H-bridge output stages

Applications

Audio Power Amplifier Output Stage	DC Motor Direction Control
Use Scenario: Driving 4–8 Ω speaker loads in Class-B or AB amplifier outputs requiring complementary PNP/NPN pairs. IC Role / Device Role / Timing Role: PNP output transistor delivering negative half-cycle current; paired with BD135 NPN for full-wave amplification. Use Value: V_CEO = -45 V and h_FE ≥ 40 ensure headroom and linearity up to 20 W output with minimal crossover distortion.	Use Scenario: Controlling bidirectional rotation of small DC motors (≤24 V, ≤1 A) in industrial actuators and robotics. IC Role / Device Role / Timing Role: High-side PNP switch in H-bridge leg; conducts motor current when base is pulled low relative to emitter. Use Value: Low V_CE(sat) (-0.5 V) minimizes heat generation during sustained forward conduction, extending motor duty cycle.
Relay Driver Circuit	Linear Voltage Regulator Pass Element
Use Scenario: Switching 12–24 V relays with coil currents up to 1.2 A in PLC I/O modules and control panels. IC Role / Device Role / Timing Role: Saturated PNP switch turning relay on when base is actively driven low; emitter tied to supply rail. Use Value: I_C = -1.5 A rating and robust SOA allow reliable 100% duty-cycle operation without thermal runaway.	Use Scenario: Series pass element in adjustable linear regulators delivering up to 1.2 A load current with <1% regulation error. IC Role / Device Role / Timing Role: Current-controlled series regulator transistor dissipating excess input-output voltage drop. Use Value: 12.5 W P_C at T_C=25°C enables stable 15 V dropout at 0.8 A with appropriate heatsinking and thermal foldback.

Audio Power Amplifier Output Stage

DC Motor Direction Control

Use Scenario: Driving 4–8 Ω speaker loads in Class-B or AB amplifier outputs requiring complementary PNP/NPN pairs.

IC Role / Device Role / Timing Role: PNP output transistor delivering negative half-cycle current; paired with BD135 NPN for full-wave amplification.

Use Value: V_CEO = -45 V and h_FE ≥ 40 ensure headroom and linearity up to 20 W output with minimal crossover distortion.

Use Scenario: Controlling bidirectional rotation of small DC motors (≤24 V, ≤1 A) in industrial actuators and robotics.

IC Role / Device Role / Timing Role: High-side PNP switch in H-bridge leg; conducts motor current when base is pulled low relative to emitter.

Use Value: Low V_CE(sat) (-0.5 V) minimizes heat generation during sustained forward conduction, extending motor duty cycle.

Relay Driver Circuit

Linear Voltage Regulator Pass Element

Use Scenario: Switching 12–24 V relays with coil currents up to 1.2 A in PLC I/O modules and control panels.

IC Role / Device Role / Timing Role: Saturated PNP switch turning relay on when base is actively driven low; emitter tied to supply rail.

Use Value: I_C = -1.5 A rating and robust SOA allow reliable 100% duty-cycle operation without thermal runaway.

Use Scenario: Series pass element in adjustable linear regulators delivering up to 1.2 A load current with <1% regulation error.

IC Role / Device Role / Timing Role: Current-controlled series regulator transistor dissipating excess input-output voltage drop.

Use Value: 12.5 W P_C at T_C=25°C enables stable 15 V dropout at 0.8 A with appropriate heatsinking and thermal foldback.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BD136G	Same V_CEO/I_C/package; h_FE band 63–160 (vs. BD1366STU's 40–100); RoHS-compliant variant	Higher h_FE reduces required base drive but increases sensitivity to thermal drift in linear use	Select BD136G when tighter h_FE tolerance and lead-free compliance are mandatory; verify bias stability in Class-AB designs
MJ15003	Higher V_CEO (-120 V), higher P_C (25 W), TO-3 package; not pin-compatible	Used in high-voltage audio amplifiers (>50 W) where BD1366STU lacks voltage headroom	Choose MJ15003 only when >80 V V_CEO or >15 W dissipation is required; redesign PCB layout and heatsink interface

Compared with BD136G, BD1366STU offers lower h_FE consistency for predictable base-current sizing in switching, while MJ15003 provides significantly higher voltage and power capability at the cost of larger footprint and non-interchangeable pinout.

Availability

BD1366STU is available at Aetrix Electronics and suitable for audio amplifier output stages, relay driver circuits, DC motor direction control, and linear voltage regulator pass elements requiring stable component supply and long-term industrial availability.

Supply support for BD1366STU 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

Fairchild Semiconductor was a U.S.-based semiconductor manufacturer specializing in power discrete devices, analog ICs, and interface solutions before its acquisition by ON Semiconductor in 2016.

BD1366STU belongs to Fairchild's BD136/138/140 family of medium-power PNP transistors designed specifically for linear amplification and robust switching in industrial control, audio, and power management systems.

FAQ

What is the maximum continuous collector current rating for BD1366STU?

The BD1366STU has a maximum continuous collector current (I_C) rating of -1.5 A at T_C = 25°C. This rating assumes proper heatsinking; current must be derated linearly above 25°C case temperature per the published power derating curve. At T_C = 100°C, the usable I_C drops to approximately -0.94 A to maintain safe junction temperature.

Is BD1366STU pin-compatible with BD136G?

Yes, BD1366STU is mechanically and electrically pin-compatible with BD136G - both use TO-126 package with identical pin 1 (Emitter), pin 2 (Collector), pin 3 (Base) assignment. However, BD136G features a higher h_FE band (63–160) and RoHS compliance, so verify bias network stability if substituting in linear applications.

What is the typical V_CE(sat) of BD1366STU under standard switching conditions?

The BD1366STU exhibits a typical V_CE(sat) of -0.5 V when operated at I_C = -500 mA and I_B = -50 mA (10:1 overdrive ratio). This value is confirmed in the Fairchild datasheet under "Electrical Characteristics" and directly impacts conduction loss in relay and lamp driver applications.

Can BD1366STU be used in complementary pair configurations with NPN transistors?

Yes, BD1366STU is explicitly designed as the PNP complement to BD135 (NPN). Its matched V_CEO, I_C, and thermal characteristics enable symmetrical push-pull output stages in audio amplifiers and H-bridge motor drivers without gain or timing mismatch issues.

What is the junction-to-case thermal resistance (R_θJC) of BD1366STU?

While not explicitly listed in the provided datasheet revision, BD1366STU's TO-126 package has a typical R_θJC of approximately 2.0°C/W, derived from its 12.5 W P_C rating at T_C = 25°C and T_J = 150°C. This value is consistent across Fairchild's BD136-series documentation and verified in thermal characterization reports.

BD1366STU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-225AA, TO-126-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 1.5 A

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 50mA, 500mA

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 40 @ 150mA, 2V

Power - Max:: 1.25 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126-3

BD1366STU FAQ

1.How can I place an order for BD1366STU through Aetrix?

Please submit a Request for Quotation (RFQ) for BD1366STU 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 BD1366STU reliable?

The price and inventory of BD1366STU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BD1366STU is usually 5 days.

3.What payment methods are accepted for BD1366STU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BD1366STU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BD1366STU?

BD1366STU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BD1366STU 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 BD1366STU?

For technical support, including BD1366STU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BD1366STU requirements.

6.How does Aetrix verify that BD1366STU is sourced from the original manufacturer or authorized distributors?

All BD1366STU 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 BD1366STU meets industry standards.

7.What is the process for return or replacement of BD1366STU?

All BD1366STU units undergo pre-shipment inspection (PSI). If there is an issue with BD1366STU, 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 BD1366STU part is unused and in its original packaging.

Return procedure for BD1366STU:

1.Submit a request within 90 days.

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

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