onsemi BD37516STU

Overview

BD37516STU from Fairchild Semiconductor is an NPN epitaxial silicon transistor in TO-126 package, rated for 80 V V_CEO, 2 A continuous collector current, and 25 W 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 BD37516STU datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 80 V, h_FE = 100–250 (Class 16), V_CE(sat) = 1 V @ I_C = 1 A / I_B = 0.1 A, and safe operating area compliance up to 150°C junction temperature.

Technical Context

This device belongs to the BD375/377/379 family of medium-power NPN transistors, with BD37516STU corresponding to the BD379 variant (V_CEO = 80 V, V_CBO = 100 V). It features a DC current gain classification of "16", indicating h_FE1 = 100–250 at V_CE = 2 V, I_C = 0.15 A.

Designed for linear and switching operation, it supports pulsed collector current up to 3 A (PW = 350 µs, duty cycle = 2%), exhibits t_ON = 50 ns and t_OFF = 500 ns under specified test conditions, and maintains ICBO ≤ 2 µA at V_CB = 80 V.

Key Specifications

Pinout & Package

BD37516STU is housed in a TO-126 plastic package with integral metal tab for heatsinking. Pin 1 is Emitter, Pin 2 is Collector (connected to tab), Pin 3 is Base - standard configuration for medium-power NPN transistors requiring mechanical mounting and thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BD37516STU, MJD31C offers higher voltage and current headroom but demands board redesign, while BD379G provides identical performance in a RoHS-compliant package-making it the preferred alternative for continuity in existing TO-126 layouts.

Availability

BD37516STU is available at Aetrix Electronics and suitable for audio amplifier output stages, DC motor drivers, relay interface circuits, and linear regulator pass elements requiring stable component supply across long-lifecycle industrial programs.

Supply support for BD37516STU 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 discrete devices, analog ICs, and interface solutions before its acquisition by ON Semiconductor in 2016.

BD37516STU belongs to the BD375/377/379 family of medium-power NPN transistors designed for linear amplification and robust switching in industrial control, audio, and power management systems.

FAQ

What is the exact package type and pin configuration of BD37516STU?

BD37516STU uses the TO-126 package with three leads: Pin 1 is Emitter, Pin 2 is Collector (internally connected to the metal tab), and Pin 3 is Base. This configuration is confirmed in the Fairchild datasheet Rev. A (February 2000), Figure "Package Dimensions" and "Pin Identification" section. The metal tab must be electrically isolated from the PCB ground plane unless Collector is at ground potential.

What does the "16" in BD37516STU signify?

The "16" in BD37516STU denotes the h_FE classification bin, specifying that the device has a DC current gain (h_FE1) of 100–250 when measured at V_CE = 2 V and I_C = 0.15 A. This binning ensures consistent gain behavior across units, critical for stable biasing in linear amplifier designs and predictable base drive in switching applications using BD37516STU.

Is BD37516STU suitable for switching applications at 10 kHz?

Yes, BD37516STU supports switching at 10 kHz. Its t_ON = 50 ns and t_OFF = 500 ns yield a minimum practical period of ~1 µs, well below the 100 µs period of 10 kHz. However, thermal management is essential: at 10 kHz with 50% duty cycle and 1 A peak current, average power must remain within the SOA envelope, especially considering PC derating above T_C = 25°C per Figure 5 in the BD37516STU datasheet.

What is the maximum allowable junction temperature for BD37516STU?

The maximum junction temperature (T_J) for BD37516STU is 150°C, as specified in the Absolute Maximum Ratings table. Operation beyond this limit risks permanent degradation of h_FE, increased leakage, or bond wire failure. To maintain reliability, designers must ensure θ_JA and θ_JC values-combined with ambient temperature and power dissipation-keep actual T_J ≤ 150°C, referencing the "Power Derating" curve (Figure 5) in the BD37516STU datasheet.

How does BD37516STU compare to BD37710STU in terms of voltage rating?

BD37516STU is the BD379 variant with V_CEO = 80 V and V_CBO = 100 V, whereas BD37710STU is the BD377 variant rated for V_CEO = 60 V and V_CBO = 75 V. This 20 V difference in collector-emitter blocking capability makes BD37516STU suitable for higher-voltage rails (e.g., 48 V systems), while BD37710STU is limited to ≤60 V applications. Both share identical TO-126 packaging and pinout.