onsemi BD1366S

Overview

BD1366S 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 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 BD1366S datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_CEO/V_CBO ratings, h_FE classification (6/10/16), saturation voltage at I_C=−500 mA/I_B=−50 mA, thermal derating curve, and complementary pairing with BD135.

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 up to 100 µs pulse width with DC and pulsed current limits clearly differentiated.

V_CE(sat) = −0.5 V at I_C = −500 mA and I_B = −50 mA confirms low-loss switching capability; V_BE(on) = −1.0 V at I_C = −0.5 A establishes base drive requirements. Junction temperature is rated to 150°C with storage range from −55°C to +150°C.

Key Specifications

Pinout & Package

BD1366S uses the TO-126 plastic package with standard 3-pin configuration: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base. The package features a metal tab for mechanical mounting and thermal conduction to heatsinks.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BD136 and MJD127, BD1366S provides optimal balance of voltage rating, gain consistency, and TO-126 thermal-mechanical fit for cost-sensitive 12–24 V linear and switching circuits where precise h_FE binning and compact heatsinking matter.

Availability

BD1366S is available at Aetrix Electronics and suitable for audio amplifiers, relay drivers, DC motor controls, and linear regulator designs requiring stable component supply across extended production lifecycles.

Supply support for BD1366S 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 devices before its acquisition by ON Semiconductor in 2016.

The BD1366S belongs to Fairchild's legacy medium-power bipolar transistor family designed for robust, cost-effective linear amplification and switching in industrial, consumer, and automotive-qualified systems.

FAQ

What is the pin configuration of BD1366S?

The BD1366S uses a TO-126 package with three terminals: Pin 1 is Emitter, Pin 2 is Collector, and Pin 3 is Base. This arrangement matches industry-standard PNP transistor orientation and is confirmed in Fairchild's BD136/138/140 datasheet Rev. A. The metal tab is electrically connected to the collector, requiring insulation when mounted to grounded heatsinks. BD1366S shares identical pinout with BD136.

Is BD1366S electrically identical to BD136?

Yes - BD1366S is a marking variant of the BD136 transistor. All absolute maximum ratings, electrical characteristics (including V_CEO, I_C, h_FE bins, V_CE(sat)), thermal specs, and package dimensions match BD136 exactly per Fairchild's official documentation. No functional or parametric deviation exists between BD1366S and BD136.

What is the maximum safe continuous collector current for BD1366S?

The maximum continuous collector current for BD1366S is −1.5 A at case temperature T_C = 25°C. At higher case temperatures, current must be derated linearly per the power derating curve in the datasheet - e.g., at T_C = 75°C, the usable I_C drops to approximately −0.9 A. Exceeding this limit risks thermal runaway or permanent junction damage.

Does BD1366S have a specified hFE classification, and how is it marked?

Yes - BD1366S is offered in three h_FE gain classifications: 6 (h_FE = 40–100), 10 (63–160), and 16 (100–250), measured at V_CE = −2 V and I_C = −150 mA. These bins are marked on the device body using alphanumeric codes (e.g., "6", "10", "16") adjacent to the part number, enabling precise bias selection in production amplifier designs.

Can BD1366S be used as a direct replacement for BD138 or BD140?

No - BD1366S is functionally equivalent only to BD136 (−45 V rating). BD138 (−60 V) and BD140 (−80 V) have higher voltage ratings and distinct h_FE distributions; substituting BD1366S in their place risks premature breakdown in circuits operating above −45 V. Always verify V_CEO and V_CBO against system rail voltages before cross-replacement.