onsemi 2SC3451M

Overview

2SC3451M from SANYO is an NPN triple diffused planar silicon transistor designed for high-voltage switching regulator applications, featuring 500 V V_CEO, 15 A I_C, 100 W P_C, 0.1 µs typical fall time (t_f), and TO-3PB package. It delivers high-speed switching performance in offline SMPS and DC-DC converters.

For engineers reviewing the 2SC3451M datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin, safe operating area (ASO) under reverse-bias conditions, h_FE classification (L/M/N ranks), thermal resistance profile, and pulse current capability (I_CP = 25 A).

Technical Context

This device uses SANYO's MBIT process to achieve wide forward- and reverse-bias ASO, supporting robust operation in hard-switched flyback and forward converter topologies. Its 500 V V_CEO rating enables direct use in 400 V DC bus designs without series stacking.

The transistor exhibits graded h_FE bins (L: 50–100, M: 80–160, N: 120–240 at V_CE = 5 V, I_C = 1.2 A), with V_CE(sat) ≤ 1.0 V and V_BE(sat) ≤ 1.4 V under I_C/I_B = 5, ensuring predictable drive requirements in gate-controlled switching stages.

Key Specifications

Pinout & Package

SANYO TO-3PB metal package with isolated collector tab, 3-pin through-hole configuration, and mechanical dimensions per drawing 2022A (unit: mm). Mounting requires insulating washer and torque control (0.5–0.7 N·m) due to integrated heat slug.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage switching transistor applications.

Compared with 2SC3451M, the base variant offers identical performance with different packaging compliance, while STW20NM50 trades bipolar ruggedness and gain linearity for MOSFET drive efficiency and reduced gate charge-making it preferable only in ZVS or high-frequency resonant converters where bipolar switching loss dominates.

Availability

2SC3451M is available at Aetrix Electronics and suitable for offline AC-DC adapters, industrial DC-DC converters, and uninterruptible power supplies requiring stable component supply and long-term manufacturability.

Supply support for 2SC3451M 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 Electric Co., Ltd. was a Japanese semiconductor manufacturer specializing in power devices, optoelectronics, and analog ICs before its acquisition by Panasonic in 2011.

The 2SC3451M belongs to SANYO's high-voltage bipolar transistor product line, engineered specifically for reliability-critical switching regulator applications in industrial and infrastructure power systems.

FAQ

What is the maximum junction temperature rating for the 2SC3451M?

The 2SC3451M has a maximum junction temperature (T_j) of 150°C, as specified in its Absolute Maximum Ratings table. This limit applies under all operating conditions, including pulsed operation. Exceeding 150°C risks permanent degradation of the triple diffused planar structure. Thermal design must ensure that T_j remains below this threshold using the published R_th(j-c) = 1.25°C/W and transient thermal data (ITR05556).

Does the 2SC3451M support parallel operation, and what precautions are needed?

Yes, the 2SC3451M supports parallel operation when matched h_FE bins (e.g., all N-rank) are used and emitter ballasting resistors (0.1–0.22 Ω) are implemented. The MBIT process ensures uniform current sharing up to 3 devices, but thermal coupling must be minimized via separate heatsinks or thermally isolated mounting. The 2SC3451M's V_BE(sat) variation (±0.2 V) necessitates individual base drive impedance tuning to prevent current hogging.

What is the significance of the "M" suffix in 2SC3451M?

The "M" suffix in 2SC3451M indicates compliance with J-STD-020 moisture sensitivity level (MSL) 3, meaning the device must be assembled within 168 hours after opening its dry-pack moisture barrier bag. It also denotes tape-and-reel packaging optimized for automated pick-and-place equipment. Electrically and functionally, 2SC3451M is identical to the base 2SC3451; the "M" reflects handling and packaging specifications-not performance differences.

Can the 2SC3451M be used in linear amplifier applications?

No, the 2SC3451M is not recommended for linear amplifier applications. Its Safe Operating Area (ASO) is optimized for switching duty cycles (PW ≤ 300 µs, duty ≤ 10%), and its SOA curves show rapid compression beyond V_CE > 100 V in linear mode. The 2SC3451M lacks guaranteed linearity parameters (e.g., f_T flatness, distortion metrics) and is characterized exclusively for switching regulator use per ENN1577B specification.

How does the 2SC3451M's reverse-bias ASO compare to its forward-bias ASO?

The 2SC3451M's reverse-bias ASO (ITR05558) is explicitly rated and graphed, confirming safe operation with V_BE = –5 V and inductive loads up to 100 µH at T_c = 25°C. Its forward-bias ASO (ITR05557) extends further due to inherent bipolar ruggedness, but both are validated-unlike many transistors where only forward ASO is specified. This dual-ASO validation makes the 2SC3451M particularly suitable for flyback and forward converters with active clamp or synchronous rectification.