onsemi 2SC4428M

Overview

2SC4428M from SANYO Semiconductor is an NPN triple-diffused planar silicon transistor designed for high-voltage switching regulator applications, featuring V_CEO = 800 V, I_C = 6 A, and t_f = 0.3 µs typ. It employs MBIT process technology, delivers high-speed switching with t_on = 0.5 µs, and operates reliably up to T_j = 150 °C in TO-3PML package.

For engineers reviewing the 2SC4428M datasheet, pinout, applications, or equivalent options, key selection criteria include its 800 V V_CEO, 6 A continuous collector current, 0.3 µs fall time, wide ASO capability, and suitability for offline SMPS primary-side switching where high breakdown voltage and thermal robustness are critical.

Technical Context

The 2SC4428M is a single NPN bipolar junction transistor optimized for hard-switched flyback and forward converter primary-side operation. Its 1100 V V_CBO, 800 V V_CEO, and 800 V V_CEX(sus) support high-input-line AC/DC designs, while its 15 MHz f_T and 0.5 µs/3.0 µs/0.3 µs (t_on/t_stg/t_f) switching profile enables efficient operation at 20–100 kHz switching frequencies.

It uses a mica-less TO-3PML package with validated pinout (Base–Collector–Emitter), rated for 55 W at T_c = 25 °C and capable of sustaining 20 A pulsed collector current under PW ≤ 300 µs / duty ≤ 10%. Its h_FE is rank-classified (K/L/M) with h_FE1 = 10–40 at I_C = 0.4 A and h_FE2 = 8 min at I_C = 2 A.

Key Specifications

Pinout & Package

SANYO TO-3PML (mica-less metal package) with isolated collector tab, 3-pin through-hole configuration, 22.0 mm × 20.4 mm footprint, and 16.0 mm height. Designed for direct bolt-down heatsinking and high-reliability industrial mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SC4428M, the 2SC4793 offers superior voltage headroom at reduced current capacity, while the BU508A trades faster switching for higher current and legacy packaging-making the 2SC4428M optimal for balanced 200–300 W SMPS where size, speed, and ruggedness intersect.

Availability

2SC4428M is available at Aetrix Electronics and suitable for industrial AC/DC power supplies, UPS inverter stages, and LED streetlight drivers requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 2SC4428M 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 2011.

The 2SC4428M belongs to SANYO's high-voltage bipolar transistor product line, engineered specifically for ruggedized switching regulator primary-side operation in industrial and infrastructure power systems.

FAQ

What is the maximum continuous collector current rating for the 2SC4428M?

The 2SC4428M has a maximum continuous collector current I_C of 6 A at T_a = 25 °C. Derating is required above ambient temperature - for example, at 70 °C ambient, the usable I_C drops to approximately 3.5 A per the PC–Ta curve in the datasheet. This rating assumes proper heatsinking and adherence to the specified thermal resistance limits.

Does the 2SC4428M support avalanche operation, and if so, under what conditions?

Yes, the 2SC4428M supports controlled avalanche operation, evidenced by its specified V_CEX(sus) = 800 V under clamped inductive switching (I_C = 3 A, I_B1 = 0.6 A, I_B2 = –0.6 A, L = 1 mH). This rating confirms repeatable energy handling without parametric shift, provided case temperature remains ≤120 °C and pulse duration stays within safe SOA boundaries.

What is the h_FE classification system for the 2SC4428M, and how is it indicated in the part number?

The 2SC4428M uses a three-rank h_FE1 classification (K: 10–20, L: 15–30, M: 20–40) at V_CE = 5 V and I_C = 0.4 A. The suffix "M" in 2SC4428M explicitly denotes the highest-gain rank (20–40), enabling predictable base drive design and minimizing required driver current in high-efficiency SMPS.

Can the 2SC4428M be used in parallel configurations, and what precautions are necessary?

Parallel operation of 2SC4428M devices is feasible but requires careful attention to emitter ballasting resistors (typically 0.1–0.22 Ω) and matched h_FE ranks to ensure current sharing. Thermal coupling between devices must be minimized, and base drive impedance should be identical. The datasheet does not guarantee inherent current-sharing behavior, so validation under worst-case load and temperature is mandatory.

What is the recommended gate/base drive circuit for optimal switching performance of the 2SC4428M?

For optimal 2SC4428M switching, use a low-impedance push-pull base driver capable of ±1.6 A peak current (per the test circuit), with 50 Ω series termination near the base pin to suppress ringing. A negative turn-off bias (–5 V) is recommended to reduce storage time, and the base-emitter path must include a reverse diode (e.g., 1N4148) to clamp negative excursions during fast transitions.