onsemi KSD569RTU

Overview

KSD569RTU from ON Semiconductor (formerly Fairchild) is an NPN epitaxial silicon power transistor in TO-220 package, rated for 80 V V_CEO, 7 A DC collector current, and 40 W collector dissipation at T_C = 25°C, used in low-frequency power amplification and industrial switching applications.

For engineers reviewing the KSD569RTU datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 80 V, I_C = 7 A, h_FE range of 40–200 (R/O/Y classification), V_CE(sat) ≤ 0.5 V at I_C = 5 A/I_B = 0.5 A, and TO-220 thermal performance with case temperature derating.

Technical Context

The KSD569RTU operates as a medium-power, low-speed switching and linear amplification device with fixed three-terminal NPN topology. Its design targets industrial control loads and audio output stages where robust SOA, moderate gain, and stable saturation characteristics are required under continuous or pulsed DC conditions.

It features complementary pairing with KSB707/KSB708 PNP transistors, supports pulse operation up to 15 A (PW ≤ 300 µs, duty ≤ 10%), and exhibits junction temperature limits of 150°C with storage range from –55°C to +150°C.

Key Specifications

Pinout & Package

Package: TO-220 (3-lead, through-hole, insulated tab). Standard outline per Fairchild Rev. A (Feb 2000), with mechanical dimensions including 15.90 mm height, 10.08 mm width, and 18.95 mm max length.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD127G and KSC2690A, the KSD569RTU offers optimal balance of 80 V/7 A rating, TO-220 through-hole compatibility, and proven industrial thermal behavior-making it preferred for retrofit, repair, and cost-sensitive through-hole power designs.

Availability

KSD569RTU is available at Aetrix Electronics and suitable for industrial motor control, audio power amplification, DC-DC converter switching, and linear power supply regulation requiring stable component supply and long-term obsolescence mitigation.

Supply support for KSD569RTU 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 (acquired Fairchild Semiconductor in 2016) is a global semiconductor supplier focused on energy-efficient power management, analog, and discrete solutions.

The KSD569RTU belongs to Fairchild's legacy low-frequency power transistor family, engineered specifically for industrial switching and linear amplification where ruggedness, thermal stability, and predictable SOA are prioritized over RF or high-speed switching performance.

FAQ

What is the maximum collector-emitter voltage rating for KSD569RTU?

The KSD569RTU has a maximum collector-emitter voltage (V_CEO) rating of 80 V at T_C = 25°C. This rating defines the upper limit for safe operation in common-emitter configuration under DC or low-frequency conditions. Exceeding this voltage risks avalanche breakdown. The KSD569RTU datasheet confirms this value in its Absolute Maximum Ratings table and distinguishes it from the KSD568RTU, which is rated at 60 V V_CEO.

Does KSD569RTU support pulse operation, and what are the limits?

Yes, the KSD569RTU supports pulsed collector current up to 15 A, provided pulse width does not exceed 300 µs and duty cycle remains ≤10%. These conditions are specified in the Absolute Maximum Ratings section of the Fairchild datasheet. Pulse testing uses stricter conditions (PW ≤ 350 µs, duty ≤ 2%) for characterization, but the 300 µs/10% limit applies to real-world intermittent operation. The KSD569RTU must be thermally managed accordingly during such pulses.

What is the pin configuration of KSD569RTU, and how is the tab connected?

The KSD569RTU uses a standard TO-220 package with pinout: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter. The metal tab is electrically connected to the Collector (Pin 2), confirmed by Fairchild's package diagram and mechanical drawings. This requires electrical isolation (e.g., mica washer or sil-pad) when mounting to a grounded heatsink unless circuit topology permits collector-to-chassis connection.

How does hFE classification affect KSD569RTU selection?

The KSD569RTU is offered in R, O, and Y h_FE classifications: R = 40–80, O = 60–120, Y = 100–200 (measured at V_CE = 1 V, I_C = 3 A). This binning affects base drive design-higher h_FE variants reduce required base current for the same collector current. The KSD569RTU part number suffix does not encode classification; users must specify R/O/Y when ordering to match circuit gain requirements.

Is KSD569RTU suitable for linear regulator applications?

Yes, the KSD569RTU is suitable for series pass transistor roles in linear regulators due to its 40 W collector dissipation at T_C = 25°C, low V_CE(sat) (≤0.5 V), and stable h_FE across operating current. It can sustain ≥5 A output with appropriate heatsinking and dropout voltage margins. The KSD569RTU's SOA curve (Figure 5 in datasheet) confirms safe operation under DC bias conditions typical of linear regulation.