onsemi BD13910S

Overview

BD13910S from Fairchild Semiconductor is an NPN epitaxial silicon transistor in TO-126 package, rated for 80 V V_CEO, 1.5 A continuous collector current, and 12.5 W device dissipation at T_C = 25°C, used in medium-power linear amplification and switching applications such as audio output stages and power supply control circuits.

For engineers reviewing the BD13910S datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 80 V, h_FE classification 10 (63–160 at I_C = 150 mA), V_CE(sat) ≤ 0.5 V at I_C = 500 mA/I_B = 50 mA, safe operating area compliance, and TO-126 thermal derating behavior.

Technical Context

This discrete NPN bipolar junction transistor operates with base-emitter forward bias to control collector current flow, supporting both linear (Class-A/AB) and saturated-switching modes. Its h_FE classification of 10 specifies a guaranteed DC current gain range of 63–160 at V_CE = 2 V and I_C = 150 mA, enabling predictable bias design in amplifier and driver circuits.

The device features a maximum junction temperature of 150°C and thermal derating from 12.5 W at T_C = 25°C to zero at T_C = 150°C, requiring heatsinking in sustained high-current operation. Absolute maximum ratings include V_CBO = 80 V, V_EBO = 5 V, and I_CP = 3.0 A (pulse), defining its safe voltage/current envelope.

Key Specifications

Pinout & Package

BD13910S is housed in a TO-126 (SOT-32) 3-lead plastic package with integral heatsink tab. The case serves as the collector terminal, enabling direct mounting to heatsinks for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BD139-16, BD13910S trades gain consistency for broader h_FE tolerance (63–160 vs. 100–250), simplifying bias design in non-critical applications; versus MJE13003, BD13910S delivers better small-signal linearity and lower saturation voltage at the expense of voltage headroom.

Availability

BD13910S is available at Aetrix Electronics and suitable for audio amplifiers, DC motor drivers, linear voltage regulators, and low-power SMPS requiring stable component supply, long-term obsolescence resilience, and traceable sourcing.

Supply support for BD13910S 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.

The BD13910S belongs to Fairchild's legacy medium-power bipolar transistor family, engineered for robust linear and switching performance in industrial, consumer, and power conversion equipment.

FAQ

What is the maximum collector-emitter voltage rating for BD13910S?

The BD13910S has a maximum collector-emitter voltage (V_CEO) rating of 80 V under open-base conditions at T_C = 25°C. This rating defines the highest DC or peak repetitive voltage the device can block between collector and emitter while remaining in the off state. Exceeding this value risks avalanche breakdown and permanent damage. Designers must ensure circuit operating voltages remain within this limit, including transients and ripple components.

What does the "10" suffix in BD13910S indicate?

The "10" in BD13910S denotes the h_FE (DC current gain) classification group, specifying a guaranteed minimum-to-maximum gain range of 63–160 at V_CE = 2 V and I_C = 150 mA. This binning allows designers to select devices with predictable current amplification characteristics for bias stability. Other variants like BD139-16 offer higher gain ranges (100–250), while BD139-6 provides lower gain (40–100).

Can BD13910S be used in switching power supplies?

Yes, BD13910S is suitable for low-frequency switching applications such as flyback or forward converter primary-side transistors up to ~100 kHz, provided voltage and current limits are respected. Its 80 V V_CEO, 1.5 A I_C, and ≤0.5 V V_CE(sat) support efficient operation in sub-25 W SMPS designs. However, it is not optimized for high-frequency (>200 kHz) or high-efficiency resonant topologies where MOSFETs or RF-optimized BJTs would be preferred.

Is BD13910S pin-compatible with BD139-16 or BD139-6?

Yes, BD13910S shares identical TO-126 package dimensions, pin assignment (Emitter-Collector-Base), and mechanical footprint with BD139-16 and BD139-6. All three variants are physically interchangeable on PCBs designed for the BD139 family. However, differences in h_FE classification mean base drive circuitry may require adjustment to maintain desired operating points across gain bins.

What thermal considerations apply when using BD13910S at full power?

At full 12.5 W dissipation, BD13910S requires effective heatsinking to maintain T_C ≤ 25°C. Its thermal resistance from junction to case is approximately 10°C/W, so even modest ambient temperatures demand a heatsink with ≤2°C/W thermal resistance to avoid exceeding 150°C junction temperature. Derating begins linearly above 25°C case temperature, reaching zero dissipation at 150°C - underscoring the need for thermal monitoring in sustained high-load operation.