onsemi KSD569YTU

Overview

KSD569YTU 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 KSD569YTU datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 80 V, I_C = 7 A, h_FE range of 100–200 (Y-class), 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

This device operates as a medium-power, low-speed NPN bipolar junction transistor optimized for linear amplification and industrial switching where high h_FE and robust safe operating area (SOA) are required. It features complementary pairing with KSB707/KSB708 PNP devices and supports pulse operation up to 15 A with ≤10% duty cycle.

Its SOA is limited by secondary breakdown and thermal constraints, with power derating beginning at T_C > 25°C. The Y-class h_FE bin (100–200 at I_C = 3 A) ensures consistent gain in amplifier bias networks and base-driven switch designs.

Key Specifications

Pinout & Package

Package: TO-220 (3-lead, straight lead, insulated tab). Mounting surface is electrically connected to collector. Standard JEDEC outline with 2.54 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD127G and BD249C, the KSD569YTU offers guaranteed Y-class h_FE and insulated TO-220 packaging-critical for thermally demanding, gain-matched amplifier and industrial switch designs where heatsink integration and predictable DC gain are prioritized over raw voltage or current headroom.

Availability

KSD569YTU is available at Aetrix Electronics and suitable for audio power amplifiers, industrial relay drivers, and DC motor control systems requiring stable component supply and long-term industrial-grade availability.

Supply support for KSD569YTU 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 (formerly Fairchild Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, with leadership in power management, analog, and discrete devices.

The KSD569YTU belongs to Fairchild's legacy low-frequency power transistor family, designed specifically for industrial linear amplification and rugged switching where reliability, SOA integrity, and complementary PNP pairing are essential.

FAQ

What is the maximum continuous collector current rating for KSD569YTU?

The KSD569YTU has a maximum DC collector current (I_C) rating of 7 A at T_C = 25°C. This rating assumes adequate heatsinking; actual usable current decreases with rising case temperature per the published derating curve. At T_C = 100°C, the practical I_C limit drops to approximately 2.8 A. Always verify thermal design using the 40 W P_C spec and R_θJC = 0.625°C/W.

Is KSD569YTU pin-compatible with KSD568YTU?

Yes, KSD569YTU and KSD568YTU share identical TO-220 package, pinout (Base–Collector–Emitter), and mechanical dimensions. The primary difference is V_CEO: 80 V for KSD569YTU versus 60 V for KSD568YTU. Substitution is permissible only if the 60 V rating of KSD568YTU meets the circuit's voltage stress requirements; otherwise, KSD569YTU provides necessary margin.

What does the "Y" suffix in KSD569YTU indicate?

"Y" denotes the h_FE classification bin: KSD569YTU is binned for DC current gain (h_FE) of 100–200 at V_CE = 1 V and I_C = 3 A. This tighter gain range improves predictability in amplifier bias networks and facilitates matched-pair selection with complementary KSB708 devices. Non-Y variants (e.g., KSD569RTU, KSD569OTU) have lower h_FE ranges.

Can KSD569YTU be used in switching power supplies?

KSD569YTU is not recommended for high-frequency switching power supplies (e.g., >20 kHz) due to its relatively slow switching characteristics and lack of specified t_f/t_r or storage time. It is optimized for low-speed industrial switching (<1 kHz) and linear amplification. For SMPS, consider modern MOSFETs or RF-optimized BJTs with documented switching parameters.

Does KSD569YTU require a heatsink in all applications?

Yes-KSD569YTU must be mounted to a heatsink in any application where power dissipation exceeds ~1.5 W, as its ambient-rated power dissipation (P_C at T_A = 25°C) is only 1.5 W. Even at modest I_C and V_CE, junction temperature will exceed 150°C without thermal management. The TO-220 insulated tab enables direct heatsink attachment, making external heatsinking both necessary and straightforward.