onsemi KSH47TF

Overview

KSH47TF from ON Semiconductor is a high-voltage NPN epitaxial silicon transistor in TO-252 (DPAK) package, rated for 350 V VCBO and 250 V VCEO, with 1 A DC collector current and 15 W power dissipation at TC = 25°C. It serves as a robust switching device in offline AC-DC power supplies and high-voltage motor control circuits.

For engineers reviewing the KSH47TF datasheet, pinout, applications, or equivalent options, key selection criteria include its 250 V VCEO rating, 1 A continuous current capability, TO-252 thermal performance, and compatibility with legacy TIP47-based designs requiring surface-mount reliability.

Technical Context

The KSH47TF operates as a single NPN bipolar junction transistor optimized for high-voltage linear and switching applications. Its 150 °C maximum junction temperature and 15 W case power dissipation support thermally demanding environments when mounted on adequate copper area.

Electrical behavior is defined by hFE = 30–150 at IC = 0.3 A, VCE(sat) = 1 V at IC = 1 A/IB = 0.2 A, and fT = 10 MHz - confirming suitability for medium-speed switching up to ~100 kHz in flyback and forward converters.

Key Specifications

Pinout & Package

Package: TO-252-3L (DPAK), surface-mount, lead-formed for PCB assembly. Thermal pad on exposed drain tab (Pin 2) must be soldered to copper pour for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KSH47TF, MJD47T4G trades higher current for lower voltage margin and gain consistency, while TIP47G retains identical voltage/current ratings but sacrifices thermal efficiency and surface-mount compatibility - making KSH47TF optimal for new SMT designs needing 250 V switching headroom and DPAK thermal advantages.

Availability

KSH47TF is available at Aetrix Electronics and suitable for offline AC-DC power supplies, industrial motor controllers, and DC-DC converter bias supplies requiring stable component supply and long-term manufacturability.

Supply support for KSH47TF 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 KSH47TF belongs to ON Semiconductor's high-voltage discrete transistor product line, designed specifically for cost-sensitive, thermally constrained industrial power conversion applications requiring ruggedness and long-lifecycle support.

FAQ

What is the maximum collector-emitter voltage rating for KSH47TF?

The KSH47TF has a maximum collector-emitter sustaining voltage (VCEO(sus)) of 250 V under test conditions of IC = 30 mA and IB = 0. This rating defines its safe operating limit in common-emitter switching configurations and is confirmed in the official ON Semiconductor datasheet revision 1.1.0. Designers must ensure voltage transients remain below this value with appropriate derating for reliability. The KSH47TF is not rated for 400 V like the KSH50TF variant.

Is KSH47TF pin-compatible with TIP47?

Yes, the KSH47TF is electrically and mechanically compatible with the TIP47, sharing identical pinout (Base–Collector–Emitter) and functional specifications including 350 V VCBO and 250 V VCEO. However, the KSH47TF uses a TO-252 (DPAK) surface-mount package versus TIP47's TO-220 through-hole form factor - so PCB layout differs, though schematic integration remains identical. The KSH47TF replaces TIP47 in new SMT designs.

What thermal design guidance applies to KSH47TF in TO-252 package?

KSH47TF delivers 15 W power dissipation at TC = 25°C, requiring a minimum 250 mm² copper area (2 oz thickness) connected to its exposed collector pad (Pin 2) for thermal compliance. Without adequate copper, junction temperature rises rapidly - exceeding 150 °C at >8 W. Thermal simulation or IR measurement is recommended for each board layout. The KSH47TF datasheet specifies θJC = 2.0 °C/W and θJA ≈ 80 °C/W with standard JEDEC 2S2P test board.

Does KSH47TF support pulse operation beyond its DC current rating?

Yes, the KSH47TF supports pulsed collector current (ICP) up to 2 A under conditions of pulse width ≤ 300 μs and duty cycle ≤ 2%, as specified in the Absolute Maximum Ratings table. This enables short-duration surge handling in motor startup or inrush limiting circuits. However, sustained operation above 1 A DC will exceed thermal limits unless aggressively cooled. Always verify pulse stress against the SOA curve in the KSH47TF datasheet.

What is the typical DC current gain (hFE) of KSH47TF at operating conditions?

The KSH47TF exhibits hFE ranging from 30 to 150 when measured at VCE = 10 V and IC = 0.3 A, and drops to ≥10 at IC = 1 A. This wide gain spread reflects process variation and necessitates base drive design accommodating the minimum value for guaranteed saturation. Unlike precision amplifiers, the KSH47TF is intended for switching - so hFE is used to size base resistors, not for linear amplification. The KSH47TF datasheet confirms these values in the Electrical Characteristics table.