onsemi FJE3303H2

Overview

FJE3303H2 from Fairchild Semiconductor is a high-voltage, fast-switching NPN power transistor in TO-126 package, rated for 700 V VCBO, 400 V VCEO, and 1.5 A DC collector current. It delivers 4 MHz fT, 21 pF Cob, and switching times of 1.1 µs tON / 0.7 µs tF, optimized for electronic ballast and switching regulator circuits operating up to 150°C junction temperature.

For engineers reviewing the FJE3303H2 datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin, saturation voltage at 1.5 A, safe operating area under pulse loads, thermal derating above 25°C, and hFE classification H2 (14–21 at IC = 0.5 A).

Technical Context

This device employs epitaxial planar construction with rugged high-voltage process technology to sustain 700 V collector-base blocking while maintaining fast minority-carrier recombination for sub-microsecond switching. Its hFE classification H2 guarantees minimum DC current gain of 14 at IC = 0.5 A and VCE = 2 V, enabling stable base drive design in high-side switch configurations.

The FJE3303H2 exhibits low VCE(sat) of 1.0 V at IC = 1.0 A / IB = 0.25 A and 3.0 V at IC = 1.5 A / IB = 0.5 A, supporting efficient operation in hard-switched topologies. Its 21 pF output capacitance and 4 MHz fT reflect a balanced trade-off between voltage rating and switching speed for 20 W–50 W power stages.

Key Specifications

Pinout & Package

Package: TO-126, thermally enhanced through-hole plastic package with metal tab (collector-connected), suitable for PCB mounting with heatsink interface via tab screw or clip.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD31C and BU508A, the FJE3303H2 uniquely balances 700 V blocking, sub-microsecond switching, and H2-classified hFE in a compact TO-126 package-making it optimal for space-constrained 20–40 W electronic ballasts and mid-power SMPS where voltage margin and thermal footprint are jointly critical.

Availability

FJE3303H2 is available at Aetrix Electronics and suitable for electronic ballast, switching regulator, and LED driver applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial and lighting OEM programs.

Supply support for FJE3303H2 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 management, analog, and discrete devices before its acquisition by ON Semiconductor in 2016.

The FJE3303H2 belongs to Fairchild's high-voltage bipolar transistor product line, engineered specifically for energy-efficient lighting and compact power conversion where high breakdown voltage and fast switching coexist in cost-sensitive through-hole packages.

FAQ

What is the guaranteed hFE range for FJE3303H2?

The FJE3303H2 is classified as H2, meaning its DC current gain (hFE) is guaranteed between 14 and 21 when measured at VCE = 2 V and IC = 0.5 A. This binning ensures predictable base drive requirements across manufacturing lots and simplifies bias network design in linear or switching applications. The FJE3303H2 maintains this specification over the full operating temperature range from –65°C to +150°C.

Can FJE3303H2 replace FJE3303H1 in existing designs?

Yes, the FJE3303H2 is a direct replacement for FJE3303H1 in most applications, as both share identical absolute maximum ratings, package, pinout, and electrical test conditions. The only difference is hFE binning: H1 specifies 8–16, while H2 guarantees 14–21. Therefore, the FJE3303H2 offers tighter gain consistency and may improve stability in base-current-sensitive circuits without requiring layout or bill-of-material changes.

What is the maximum allowable case temperature for FJE3303H2?

The FJE3303H2 has a maximum junction temperature (TJ) of 150°C, and its power dissipation must be derated linearly above TC = 25°C at 0.16 W/°C, as shown in Figure 9 of the datasheet. For reliable long-term operation, the case temperature should remain below 100°C under continuous load, assuming proper heatsinking. The FJE3303H2's TO-126 metal tab must be electrically isolated from the heatsink unless intentionally connected to the collector node.

Does FJE3303H2 support avalanche energy rating?

No, the FJE3303H2 datasheet does not specify an avalanche energy (EAS) rating or ruggedness test data. It is not characterized for repetitive unclamped inductive switching. Designers must ensure that all inductive energy is safely clamped using external snubbers or RCD networks. The FJE3303H2 is intended for applications with controlled turn-off and well-defined SOA boundaries-not for unprotected flyback or motor drive switching where avalanche stress is expected.

What is the recommended base resistor value for FJE3303H2 at 1.5 A collector current?

At IC = 1.5 A and assuming minimum hFE(H2) = 14, the required base current is ≥107 mA. To ensure saturation and margin, IB should be set to ≥0.5 A (per datasheet's VCE(sat) test condition). With typical VBE(sat) ≈ 1.2 V, a 10 Ω base resistor driven from a 6 V logic source delivers ~500 mA IB. Thus, a 10 Ω ±5% resistor is recommended for robust saturation of the FJE3303H2 under worst-case gain and temperature conditions.