onsemi 2SD2281R

Overview

2SD2281R from SANYO Semiconductor is an NPN epitaxial planar silicon transistor designed for high-current switching applications such as relay drivers, high-speed inverters, and DC-DC converters. It delivers IC = 12 A continuous, V_CEO = 50 V, V_CE(sat) ≤ 0.4 V at IC = 6 A / IB = 0.3 A, f_T = 10 MHz, and operates up to T_j = 150 °C in a micaless TO-3PML package.

For engineers reviewing the 2SD2281R datasheet, pinout, applications, or equivalent options, key selection criteria include its low saturation voltage, wide ASO (Area of Safe Operation), high pulse current capability (ICP = 25 A), ruggedness against secondary breakdown, and suitability for industrial power switching where thermal robustness and fast switching (t_on = 0.1 µs, t_f = 0.5 µs) are critical.

Technical Context

The 2SD2281R is a discrete NPN bipolar junction transistor optimized for linear and saturated switching modes in medium-power applications. Its design emphasizes high current gain linearity (h_FE = 70–280 at IC = 1 A; h_FE ≥ 30 at IC = 5 A), low V_CE(sat), and stable operation under transient load conditions with specified safe operating area up to T_c = 25 °C.

It features a monolithic epitaxial planar structure with emitter ballasting for current uniformity and thermal stability. The TO-3PML package provides direct metal-to-heatsink mounting without mica insulation, enabling efficient thermal transfer and simplified mechanical assembly in high-reliability power stages.

Key Specifications

Pinout & Package

2SD2281R uses the SANYO TO-3PML package: insulated metal tab, no mica required, with base-collector-emitter terminal layout optimized for low-inductance power connections and thermal path integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current NPN switching applications.

Compared with 2SD2281R, 2SD2622 offers higher voltage headroom at the cost of increased V_CE(sat), while MJD122G trades current capacity and thermal performance for ease of PCB integration and voltage margin - selection depends on whether bus voltage, thermal management, or layout constraints dominate the design.

Availability

2SD2281R is available at Aetrix Electronics and suitable for industrial relay drivers, DC-DC converter switches, and high-speed inverter designs requiring stable component supply, consistent parametric binning, and long-lifecycle availability.

Supply support for 2SD2281R 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

SANYO Semiconductor was a Japanese semiconductor manufacturer specializing in power discrete devices, analog ICs, and optoelectronics before its acquisition by ON Semiconductor in 2013.

The 2SD2281R belongs to SANYO's high-current bipolar transistor family engineered for rugged industrial switching - emphasizing low saturation voltage, wide SOA, and mechanical robustness in TO-3PML packaging for demanding power conversion and motor control.

FAQ

What is the maximum continuous collector current rating for the 2SD2281R?

The 2SD2281R has a maximum continuous collector current (I_C) rating of 12 A at case temperature T_c = 25 °C. This rating assumes proper heatsinking and derates linearly with increasing case temperature per the published P_C vs. T_c curve. At T_c = 100 °C, the usable I_C drops to approximately 6.5 A. Always verify thermal design using the 45 W P_C limit at T_c = 25 °C when evaluating 2SD2281R in your application.

Does the 2SD2281R require a mica insulator when mounted to a heatsink?

No, the 2SD2281R uses the micaless TO-3PML package, meaning its metal tab is electrically isolated internally - no external mica or silicone pad is needed for electrical insulation. This reduces thermal resistance by ~0.5 °C/W compared to traditional TO-3 packages and simplifies mechanical assembly. However, ensure the mounting surface is flat, clean, and torqued to specification (typically 0.7–1.0 N·m) to maintain optimal thermal contact for the 2SD2281R.

What is the typical DC current gain (h_FE) of the 2SD2281R at 5 A collector current?

At V_CE = –2 V and I_C = –5 A, the 2SD2281R guarantees h_FE ≥ 30 (minimum), with typical values ranging from 45 to 75 depending on unit variation and temperature. The device is binned by h_FE at 1 A (Ranks Q/R/S), but the 5 A gain is un-binned and process-stabilized for switching consistency. This makes the 2SD2281R suitable for base-driven circuits where predictable gain at high current is essential - such as in relay drivers or inverter legs where 2SD2281R operates near saturation.

Can the 2SD2281R be used in parallel configurations for higher current handling?

Yes, the 2SD2281R can be paralleled, but only with careful attention to emitter-ballasted base drive and matched h_FE bins. Its internal emitter ballasting improves current sharing, yet mismatched thermal paths or unequal base resistances will cause current hogging. For reliable parallel operation of multiple 2SD2281R units, use individual 0.1–0.22 Ω emitter resistors, identical PCB copper pour areas, and thermally coupled mounting. Do not assume drop-in parallelism without validation in your specific layout and thermal environment.

What is the safe operating area (SOA) limitation for single-pulse operation of the 2SD2281R?

The 2SD2281R's SOA is characterized for single-pulse durations from 10 µs to 100 ms at T_c = 25 °C, supporting up to 25 A at 10 V or 10 A at 40 V. The SOA curve confirms no secondary breakdown up to these limits - critical for inductive load switching. Pulse testing must follow the specified test circuit (RB = 1 Ω, RL = 4 Ω, PW ≤ 100 µs). Exceeding SOA boundaries risks immediate thermal runaway; always validate 2SD2281R operation within the published SOA plot for your pulse width and voltage conditions.