onsemi KSD288YTU

Overview

KSD288YTU from Fairchild Semiconductor is an NPN epitaxial silicon power transistor in TO-220 package, rated for 55 V V_CEO, 3 A I_C, and 25 W P_C at T_C=25°C, used in low-frequency high-power amplifier and linear power regulator circuits.

For engineers reviewing the KSD288YTU datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain (h_FE = 40–240), collector-emitter saturation voltage (V_CE(sat) = 1 V @ I_C=1 A/I_B=0.1 A), breakdown voltage margins, thermal derating behavior, and TO-220 mechanical compatibility.

Technical Context

This discrete NPN bipolar junction transistor operates in linear or switching mode with fixed base-emitter forward bias control. Its safe operating area (SOA) is defined up to 1 ms pulse width and DC conditions, with thermal derating beginning at T_C > 25°C.

The device exhibits h_FE classification variants (R/O/Y) indicating guaranteed minimum/maximum DC current gain bands, and its V_CE(sat) and V_BE(sat) are characterized across collector current from 0.1 A to 10 A, supporting stable biasing in Class-A/B amplifier stages and series pass elements.

Key Specifications

Pinout & Package

Package: TO-220 (3-lead, straight lead form, insulated tab). Mounting surface is electrically connected to collector terminal.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD288T4 and 2SC5200, the KSD288YTU offers optimal balance of TO-220 mechanical compatibility, 55 V/3 A capability, and guaranteed h_FE binning for predictable linear amplifier and regulator design-without over-engineering or SMT conversion overhead.

Availability

KSD288YTU is available at Aetrix Electronics and suitable for linear voltage regulators, audio power amplifiers, and low-frequency DC motor drivers requiring stable component supply and long-term industrial availability.

Supply support for KSD288YTU 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 discrete devices, analog ICs, and interface solutions before its acquisition by ON Semiconductor in 2016.

The KSD288YTU belongs to Fairchild's legacy high-voltage NPN power transistor family, designed specifically for robust linear and quasi-switching operation in industrial power control and audio systems.

FAQ

What is the pin configuration of the KSD288YTU?

The KSD288YTU uses a standard TO-220 package with pin 1 = Base, pin 2 = Collector (connected to metal tab), and pin 3 = Emitter. This configuration is confirmed in Fairchild's Rev. A datasheet and matches industry-standard TO-220 NPN orientation. Always verify tab isolation requirements before heatsink mounting, as the collector is electrically exposed on the tab surface.

Does the KSD288YTU have a guaranteed h_FE range?

Yes, the KSD288YTU is factory-binned into R/O/Y classifications with guaranteed h_FE ranges: R = 40–80, O = 70–140, Y = 120–240, measured at V_CE = 5 V and I_C = 0.5 A. The suffix "YTU" corresponds to the Y-class variant, meaning the KSD288YTU specifically guarantees h_FE ≥120 and ≤240 under those test conditions.

What is the maximum power dissipation of the KSD288YTU at 75°C case temperature?

Per the power derating curve in the KSD288YTU datasheet, P_C decreases linearly from 25 W at T_C = 25°C to zero at T_C = 150°C. At 75°C case temperature, the KSD288YTU supports 16.7 W (25 W × (1 − (75−25)/125)). This value assumes proper heatsinking and no additional derating for pulse duty cycle or ambient airflow.

Can the KSD288YTU replace the KSD288 in existing designs?

Yes, the KSD288YTU is a direct variant of the KSD288 with identical electrical specifications, TO-220 package, and pinout. The "YTU" suffix denotes Y-class h_FE binning and tape-and-reel packaging per Fairchild's ordering nomenclature. No layout or schematic changes are required when substituting KSD288YTU for KSD288 in functional designs.

Is the KSD288YTU suitable for switching-mode power supply applications?

The KSD288YTU is characterized for low-frequency operation and lacks published switching parameters (t_on, t_off, storage time) in its datasheet. While it can function in non-critical 1–10 kHz switching roles, it is not optimized for high-efficiency SMPS due to relatively high V_CE(sat) and uncharacterized switching loss. For such applications, modern MOSFETs or purpose-built BJT switches like the FJP13009 are preferred over the KSD288YTU.