onsemi FJP5021OVTU

Overview

FJP5021OVTU from Fairchild Semiconductor is an NPN silicon power transistor designed for high-voltage switching applications, with 800 V collector-base breakdown voltage (BVCBO), 500 V collector-emitter sustaining voltage (VCEX(sus)), and 5 A DC collector current (IC). It features fast switching (tF = 0.1 µs typ.), low saturation voltages (VCE(sat) = 1 V at IC = 3 A, IB = 0.6 A), and operates up to 150 °C junction temperature - used in flyback converters and snubberless AC switchers.

For engineers reviewing the FJP5021OVTU datasheet, pinout, applications, or equivalent options, key selection criteria include its 500 V VCEO rating, wide forward-bias safe operating area (SOA), TO-220 package thermal performance, and verified hFE range of 20–40 (Class O) under 0.6 A bias conditions.

Technical Context

This device is a single NPN bipolar junction transistor optimized for high-voltage, medium-current switching in offline power supplies. Its rugged SOA supports unclamped inductive switching, and it delivers stable gain (hFE2 = 8–50 at IC = 3 A) with low VBE(sat) = 1.5 V, enabling efficient base drive in hard-switched topologies.

The FJP5021OVTU uses epitaxial planar construction with gold-doped base region for controlled carrier lifetime, yielding fast turn-off (tF = 0.1–0.3 µs) and minimal storage time (tSTG = 3 µs). Its Cob = 80 pF at VCB = 10 V supports predictable switching loss estimation in 20–100 kHz SMPS designs.

Key Specifications

Pinout & Package

Package: TO-220 (3-lead, straight lead, insulated tab). Case temperature rating up to 150 °C; mounting hole ø3.60 mm; thermal resistance RθJC = 1.5 °C/W (typ., with heatsink).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD127G and BU508AF, the FJP5021OVTU uniquely balances 500 V sustain voltage, 0.1 µs tF, and TO-220 thermal capability - making it optimal for cost-sensitive, 20–100 kHz flyback and phase-control designs requiring both speed and ruggedness.

Availability

FJP5021OVTU is available at Aetrix Electronics and suitable for switch-mode power supplies, AC motor controllers, induction heating inverters, and active PFC boost converters requiring stable component supply and long-term industrial availability.

Supply support for FJP5021OVTU 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 analog and power semiconductor manufacturer, acquired by ON Semiconductor in 2016; known for high-reliability discrete devices and power management ICs.

The FJP5021OVTU belongs to Fairchild's high-voltage bipolar transistor product line, engineered specifically for ruggedized switching in offline AC/DC conversion and industrial motor control where voltage margin and SOA robustness are critical.

FAQ

What is the maximum continuous collector current rating for the FJP5021OVTU?

The FJP5021OVTU has a maximum DC collector current (IC) of 5 A at case temperature TC = 25 °C. This rating decreases linearly with rising case temperature - down to 0 A at TC = 150 °C - as shown in Figure 8 of the official datasheet. Derating must be applied in real-world thermal environments, and the FJP5021OVTU requires adequate heatsinking to maintain safe junction temperature during sustained 5 A operation.

Is the FJP5021OVTU pin-compatible with other TO-220 NPN transistors like the MJE13009?

The FJP5021OVTU uses standard TO-220 pinout (1=Base, 2=Collector, 3=Emitter), matching mechanical and electrical pin assignments of MJE13009 and similar devices. However, it is not a drop-in replacement due to differences in VCEO (500 V vs. 400 V), hFE classification, and SOA characteristics. System-level validation of voltage stress, switching behavior, and thermal performance is required before substitution.

Does the FJP5021OVTU support avalanche-rated operation?

No, the FJP5021OVTU is not rated for repetitive avalanche operation. Its datasheet specifies VCEX(sus) = 500 V under clamped inductive switching (L = 1 mH, IB1 = –IB2 = 1 A), indicating designed robustness for single-pulse energy absorption - not sustained avalanche mode. For true avalanche-rated alternatives, consider ON Semiconductor's NSS series or STMicroelectronics' STD series with explicit EAS ratings.

What is the hFE classification letter for the FJP5021OVTU and how does it affect base drive design?

The "O" in FJP5021OVTU denotes hFE Class O, meaning DC current gain ranges from 20 to 40 at VCE = 5 V and IC = 0.6 A. This defines minimum base current requirements: to achieve 3 A collector current, designers must supply ≥75 mA (3 A ÷ 40) to 150 mA (3 A ÷ 20) base current. The FJP5021OVTU's specified VBE(sat) = 1.5 V further informs base resistor sizing in fixed-bias configurations.

Can the FJP5021OVTU be used in parallel configurations for higher current handling?

Parallel operation of FJP5021OVTU devices is not recommended without individual emitter ballasting resistors. Due to inherent hFE and VBE(sat) variation across units - even within Class O - current sharing becomes unstable, risking thermal runaway. If higher current is needed, select a single higher-rated device (e.g., FJP5045) or verify matched pairs with binning data from lot-specific test reports before implementing parallel use.