onsemi FJP3305

Overview

FJP3305 from ON Semiconductor is a high-voltage, fast-switching NPN power transistor in TO-220 package, rated for 700 V VCBO, 400 V VCEO, and 4 A DC collector current. It delivers 75 W collector dissipation at TC = 25°C with typical fT = 4 MHz and Cob = 65 pF, optimized for electronic ballast and switching regulator circuits requiring robust high-voltage switching.

For engineers reviewing the FJP3305 datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin (VCBO = 700 V), saturation performance (VCE(sat) = 0.5–1.0 V across 1–4 A), switching speed (tON = 0.8 ms, tF = 0.9 ms), thermal capability (TJ = 150°C), and TO-220 mechanical compatibility.

Technical Context

The FJP3305 operates as a single NPN bipolar junction transistor with fixed emitter-base and collector-base junctions, supporting linear amplification and hard-switching modes. Its design emphasizes high-voltage blocking (VCBO = 700 V) and fast turn-on/turn-off (tON/tF ≤ 0.9 ms) under inductive loads, validated per pulse test conditions (PW ≤ 300 ms, duty cycle ≤ 2%).

It features a DC current gain range of hFE1 = 19–35 at IC = 1 A and hFE2 = 8–40 at IC = 2 A, with saturation voltages specified at multiple drive levels (IB = 0.2–1 A). Output capacitance (Cob = 65 pF at VCB = 10 V) and safe operating area curves are defined for both forward- and reverse-biased conditions.

Key Specifications

Pinout & Package

Package: TO-220 (JEDEC variation AB, 3-lead, through-hole, heatsink-mountable). Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter - confirmed per datasheet mechanical drawing and absolute maximum ratings table.

Key Features

Applications

Equivalent & Alternatives

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

Compared with FJP3305, FJP13009 offers higher power handling in a different package, while MJE13009 provides TO-220 compatibility at the cost of reduced gain and higher saturation voltage-making FJP3305 optimal for 4 A, 75 W, TO-220-constrained designs.

Availability

FJP3305 is available at Aetrix Electronics and suitable for electronic ballast, switching regulator, and AC motor control applications requiring stable component supply and legacy design support.

Supply support for FJP3305 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The FJP3305 belongs to ON Semiconductor's legacy high-voltage bipolar power transistor product line, designed specifically for cost-sensitive, medium-power switching applications including lighting ballasts and offline power supplies.

FAQ

What is the maximum collector-emitter voltage rating for the FJP3305?

The FJP3305 has a maximum collector-emitter voltage (VCEO) rating of 400 V at TC = 25°C with base open. This rating defines the highest DC or peak AC voltage the device can block in common-emitter configuration without breakdown. Exceeding this value risks permanent damage. The FJP3305 datasheet specifies this parameter under standardized test conditions (IC = 5 mA, IB = 0), and actual usable voltage depends on circuit layout, snubbing, and thermal conditions.

Is the FJP3305 still recommended for new designs?

No-the FJP3305 is marked "DISCONTINUED" and "NOT RECOMMENDED FOR NEW DESIGN" in its official ON Semiconductor documentation. While Aetrix Electronics maintains limited legacy stock for repair and maintenance, new designs should consider alternatives such as FJP13009 or MJE13009 with updated support. The FJP3305 remains functional and electrically valid, but long-term supply and technical support for the FJP3305 are not assured.

What package type does the FJP3305 use, and how is it mounted?

The FJP3305 uses a TO-220AB package with three leads: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter. It is a through-hole, heatsink-mountable package where the metal tab (connected to the collector) must be electrically isolated from the heatsink using mica or silicone insulator unless circuit topology permits direct connection. Mounting requires torque-controlled screws (typically 0.4–0.6 N·m) and thermal interface material for effective heat transfer from the FJP3305 to the heatsink.

What is the DC current gain (hFE) range of the FJP3305 at 1 A collector current?

At VCE = 5 V and IC = 1 A, the FJP3305 exhibits hFE1 ranging from 19 to 35 (minimum to maximum), per its H1 and H2 classifications. This gain range is measured at TC = 25°C and reflects unit-to-unit variation within the production lot. Gain decreases with rising temperature and collector current-e.g., hFE2 drops to 8–40 at IC = 2 A-so base drive design for the FJP3305 must accommodate worst-case low-hFE units while avoiding overdrive at high temperatures.

Can the FJP3305 replace the MJE13005 in an electronic ballast circuit?

The FJP3305 can functionally replace the MJE13005 in many electronic ballast circuits due to matching voltage ratings (both 400 V VCEO, 700 V VCBO) and TO-220 packaging, but differences exist: FJP3305 offers higher IC (4 A vs 2.5 A), higher PC (75 W vs 50 W), and faster switching (tF = 0.9 ms vs ~1.2 ms). Designers must verify base drive strength, thermal margin, and snubber tuning, as the FJP3305's higher gain and lower VCE(sat) may alter timing and loss profiles in the existing MJE13005-based FJP3305 circuit.