onsemi BD1386STU

Overview

BD1386STU from Fairchild Semiconductor is a PNP epitaxial silicon transistor in TO-126 package, rated for -60 V V_CEO, -1.5 A continuous collector current, and 12.5 W case power 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 BD1386STU datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_CEO/V_CBO ratings, hFE classification (63–160 at I_C=−150 mA), V_CE(sat) ≤ −0.5 V, 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 (hFE) 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 up to 100 V and 3 A pulsed, with thermal resistance R_θJC ≈ 10°C/W implied by 12.5 W P_C at T_C=25°C.

The device features low V_BE(on) of −1.0 V at I_C = −0.5 A and exhibits negligible leakage: I_CBO ≤ −0.1 µA at V_CB = −30 V and I_EBO ≤ −10 µA at V_EB = −5 V, supporting stable biasing in temperature-varying environments.

Key Specifications

Pinout & Package

BD1386STU is housed in a TO-126 plastic package with integral metal tab for heatsink attachment. Pin 1 is Emitter, Pin 2 is Collector, Pin 3 is Base - confirmed by Fairchild's official package outline and pin identification diagram.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD13005 and BC639, BD1386STU uniquely balances −60 V blocking, −1.5 A current, and 12.5 W dissipation in TO-126 - making it irreplaceable in 24–48 V industrial switching where both voltage margin and thermal capacity are critical.

Availability

BD1386STU is available at Aetrix Electronics and suitable for audio amplifiers, relay drivers, DC motor controllers, and linear regulator designs requiring stable component supply with consistent parametric performance across production batches.

Supply support for BD1386STU 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 company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

BD1386STU belongs to Fairchild's legacy medium-power bipolar transistor family, engineered for robust linear amplification and switching in industrial control, consumer audio, and power conversion systems.

FAQ

What is the maximum continuous collector current rating for BD1386STU?

The BD1386STU has a maximum continuous collector current (I_C) rating of −1.5 A at T_C = 25°C. This value decreases with rising case temperature per the published derating curve; at T_C = 100°C, usable I_C drops to approximately −0.75 A. The BD1386STU must be mounted on an appropriate heatsink to sustain rated current in real-world conditions.

Is BD1386STU pin-compatible with BD137?

No, BD1386STU is not pin-compatible with BD137. BD1386STU is a PNP transistor in TO-126 package with pinout Emitter–Collector–Base (1–2–3), while BD137 is an NPN device with identical physical package but opposite polarity and complementary electrical characteristics. They are functional complements-not mechanical drop-in replacements.

What is the guaranteed hFE range for BD1386STU at I_C = −150 mA?

At V_CE = −2 V and I_C = −150 mA, the BD1386STU has a guaranteed hFE range of 63 to 160. This classification (hFE3) is explicitly stated in the Fairchild datasheet and enables accurate base resistor calculation for switching or linear bias networks using the BD1386STU.

Does BD1386STU require a heatsink in normal operation?

Yes, BD1386STU requires a heatsink when dissipating more than ~1 W continuously. Its 12.5 W P_C rating applies only at T_C = 25°C - a condition unattainable without forced cooling or large copper area. In typical PCB-mounted applications, a minimum 10 cm² copper pour or clip-on heatsink is recommended to keep T_J within 150°C under −1 A load.

Can BD1386STU be used in avalanche mode?

No, BD1386STU is not rated or characterized for controlled avalanche operation. Its V_CEO(sus) = −60 V is specified under non-avalanche test conditions (I_C = −30 mA, I_B = 0), and the datasheet contains no SOA data for reverse-biased second breakdown. Use in energy-clamping applications requires explicit avalanche-rated devices like FMMT series or dedicated TVS-assisted designs.