onsemi BCP68

Overview

BCP68 from ON Semiconductor is an NPN general-purpose amplifier transistor in SOT-223 package, rated for 20 V V_CEO, 1 A continuous collector current, and 1.5 W power dissipation at 25°C. It delivers DC current gain (h_FE) of 50–375 at test conditions and exhibits V_CE(sat) ≤ 0.5 V at I_C = 1 A / I_B = 100 mA, suitable for medium-power linear amplification and switching in industrial control interfaces.

For engineers reviewing the BCP68 datasheet, pinout, applications, or equivalent options, key selection considerations include its SOT-223 thermal performance, V_CEO/V_CBO voltage ratings, h_FE spread across operating currents, and verified operation over –55°C to +150°C junction temperature range.

Technical Context

The BCP68 is a silicon planar epitaxial NPN bipolar junction transistor optimized for medium-power analog amplification and saturated switching. Its design supports stable h_FE across I_C = 5 mA to 1 A with V_CE = 1–10 V bias, and features low V_CE(sat) under high-current drive conditions.

It operates within a wide junction temperature range (–55°C to +150°C), with thermal derating of 12 mW/°C above 25°C ambient, and meets breakdown voltage requirements of V_(BR)CEO = 20 V (I_C = 1 mA) and V_(BR)CBO = 30 V (I_E = 0), confirming suitability for 24 V rail interface stages.

Key Specifications

Pinout & Package

SOT-223 surface-mount package with integrated heat sink tab (pin 4). Standard pin assignment: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter, Pin 4 = Collector (thermal pad).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.

Compared with ZTX653 and MJD112, the BCP68 uniquely balances 1 A current capability, SOT-223 thermal efficiency, and 20 V V_CEO in a compact surface-mount form-making it optimal for space-constrained industrial control modules requiring reliable medium-power amplification or switching.

Availability

BCP68 is available at Aetrix Electronics and suitable for motor driver stages, industrial sensor interfaces, relay driver circuits, and power supply enable switches requiring stable component supply and consistent parametric performance across production batches.

Supply support for BCP68 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BCP68 belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild and optimized for cost-sensitive, medium-power linear and switching applications in industrial control and power interface circuits.

FAQ

What is the maximum continuous collector current rating for the BCP68?

The BCP68 has a maximum continuous collector current (I_C) rating of 1 A at T_A = 25°C. This rating decreases with rising ambient temperature due to thermal derating of 12 mW/°C above 25°C. At elevated temperatures or in enclosed environments, design margins must account for reduced current capacity to maintain reliability and avoid thermal runaway. The BCP68 datasheet specifies this limit under defined test conditions and should be validated in the final PCB layout with actual thermal management.

Does the BCP68 support operation at elevated junction temperatures?

Yes, the BCP68 is rated for junction temperatures from –55°C to +150°C. This extended range enables use in demanding industrial environments such as motor control enclosures or outdoor instrumentation where ambient temperatures exceed standard commercial limits. Operation near the upper limit requires careful thermal design-especially ensuring adequate copper area under the SOT-223 thermal pad-to prevent exceeding the 150°C maximum. The BCP68 maintains specified electrical characteristics across this full range when properly mounted.

What is the typical DC current gain (h_FE) of the BCP68 at different operating points?

The BCP68 exhibits h_FE = 50–375 depending on collector current and V_CE. At I_C = 5 mA and V_CE = 10 V, minimum h_FE is 50; at I_C = 500 mA and V_CE = 1 V, it rises to 85 (typical); and at I_C = 1 A and V_CE = 1 V, minimum h_FE is 60. These values are confirmed in the official BCP68 datasheet and reflect real-world variability-designers should use the minimum guaranteed value for worst-case bias calculations. The BCP68's h_FE profile supports both low-current signal amplification and high-current switching.

Can the BCP68 be used as a saturated switch in 24 V relay driver applications?

Yes, the BCP68 is suitable for 24 V relay driver applications when operated in saturation. Its V_(BR)CEO = 20 V and V_(BR)CBO = 30 V provide margin against flyback transients, and V_CE(sat) ≤ 0.5 V at I_C = 1 A / I_B = 100 mA ensures low conduction loss. To protect against inductive kickback, a reverse-biased flyback diode must be placed across the relay coil. The BCP68's thermal performance in SOT-223 also supports continuous relay cycling without overheating if PCB copper area is sufficient.

What is the pin configuration of the BCP68 in the SOT-223 package?

The BCP68 uses standard SOT-223 pinout: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter, Pin 4 = Collector (exposed thermal pad). Pins 2 and 4 are internally connected and must be soldered to the same net-typically a large copper pour-for thermal and electrical performance. This configuration is documented in the official BCP68 datasheet and verified on ON Semiconductor's product page. Misalignment of pin 4 in layout can cause thermal failure or parametric shift, so adherence to the BCP68 mechanical drawing is essential.