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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi KSC5338D

Name: KSC5338D
Brand: onsemi
SKU: KSC5338D
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KSC5338D

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: KSC5338D.pdf

Description:: TRANS NPN 450V 5A TO-220-3

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Product details

Overview

KSC5338D from onsemi is an NPN triple-diffused planar silicon power transistor in TO-220-3LD package, rated for 450 V V_CEO, 5 A DC collector current, and 75 W power dissipation at T_C = 25°C. It integrates a built-in free-wheeling diode and is engineered for high-voltage switching in electronic ballasts and inductive load drivers.

For engineers reviewing the KSC5338D datasheet, pinout, applications, or equivalent options, key selection criteria include its 1.65°C/W junction-to-case thermal resistance, 1.9–2.2 μs storage time under inductive switching (V_Z = 300 V), and dynamic saturation voltage of ≤8 V at 1 A/100 mA drive under 300 V conditions.

Technical Context

The KSC5338D employs a rugged triple-diffused planar structure optimized for high-voltage switching with wide safe operating area (SOA) up to 450 V and 5 A DC. Its integrated anti-parallel diode enables self-contained flyback energy handling in inductive circuits without external diode placement.

Switching performance is characterized by controlled storage time (1.2–2.2 μs) and fall time (70–330 ns) across temperature and load conditions, with forced gain (h_FE) maintained at ≥4–14 over −25°C to +125°C at I_C = 2 A, supporting stable gate drive design in ballast and SMPS half-bridge topologies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	450 V - Enables direct use in 277 VAC and 380 VDC bus applications without series stacking.
I_C (DC)	5 A - Supports continuous lamp current in 40–60 W electronic fluorescent ballasts.
P_C @ T_C=25°C	75 W - Requires heatsink with ≤1.65°C/W thermal resistance for full-power operation.
R_jc	1.65 °C/W - Defines minimum heatsink interface requirement for junction temperature control.
t_STG (inductive)	1.9–2.2 μs @ 25°C - Determines minimum off-time in PWM-controlled ballast drivers.
V_F (diode)	0.86–0.95 V @ 1–2 A - Minimizes conduction loss during freewheeling phase.
V_CE(DSAT)	2.9–9 V @ 1–2 A - Specifies dynamic saturation voltage under pulsed high-voltage switching.

Pinout & Package

Package: TO-220-3LD (Case 340AT), through-hole, isolated tab, 3-terminal configuration with metal tab electrically connected to collector.

Pin/Terminal	Circuit Role	Design Meaning
1 (Left)	Base	Control input requiring 100–400 mA peak drive for full saturation under 2–5 A loads.
2 (Center)	Collector	Main high-side switching node; electrically tied to metal tab - requires isolation from heatsink unless system ground referenced.
3 (Right)	Emitter	Power return path; low-inductance connection critical for minimizing switching overshoot in ballast resonant tanks.

Key Features

Feature	Design Value
Built-in free-wheeling diode	Enables compact ballast designs without discrete diode, reducing BOM count and layout area.
Wide SOA (Safe Operating Area)	Supports linear-mode operation up to 450 V × 5 A with no second breakdown risk under specified pulse conditions.
Small variance in storage time	±0.3 μs variation across temperature ensures consistent timing margin in fixed-frequency ballast controllers.
Pb-free and halide-free	Complies with RoHS Directive 2011/65/EU and JEDEC JS709E, suitable for global industrial production.
High V_CBO = 1000 V	Provides 2.2× overvoltage margin against transients in 400 VDC systems, enhancing reliability in unregulated supplies.

Applications

Electronic Ballast Control	AC-DC SMPS Half-Bridge
Use Scenario: Driving resonant LC tank in 220–277 VAC fluorescent lamp ballasts with frequency sweep start and constant-current regulation. IC Role / Device Role / Timing Role: Main high-side switch in half-bridge topology, synchronized with complementary low-side device via dead-time control. Use Value: Integrated diode eliminates need for external flyback diode; 1.9–2.2 μs t_STG enables precise 20–50 kHz PWM timing control.	Use Scenario: High-voltage primary-side switching in 300–400 VDC input offline SMPS for industrial power supplies. IC Role / Device Role / Timing Role: Power switch in asymmetrical half-bridge or single-ended forward converter with active clamp. Use Value: 450 V V_CEO and 75 W P_C support 100–200 W output without derating; R_jc = 1.65°C/W simplifies thermal design.
Inductive Load Driver	High-Voltage Relay Replacement
Use Scenario: Solid-state replacement for mechanical relays driving solenoids, valves, or transformers in HVAC and factory automation. IC Role / Device Role / Timing Role: Single-pole, high-voltage switching element with integrated flyback path for inductive kick suppression. Use Value: Built-in diode handles >2 A flyback currents; t_F ≤ 200 ns ensures fast turn-off for precise duty-cycle control.	Use Scenario: Replacing electromechanical relays in 240 VAC motor starter circuits and lighting control panels. IC Role / Device Role / Timing Role: Voltage-rated switching element with galvanic isolation via heatsink mounting and creepage-compliant TO-220 footprint. Use Value: 1000 V V_CBO withstands surge transients per IEC 61000-4-5; TO-220-3LD allows direct PCB mount with screw terminal compatibility.

Electronic Ballast Control

AC-DC SMPS Half-Bridge

Use Scenario: Driving resonant LC tank in 220–277 VAC fluorescent lamp ballasts with frequency sweep start and constant-current regulation.

IC Role / Device Role / Timing Role: Main high-side switch in half-bridge topology, synchronized with complementary low-side device via dead-time control.

Use Value: Integrated diode eliminates need for external flyback diode; 1.9–2.2 μs t_STG enables precise 20–50 kHz PWM timing control.

Use Scenario: High-voltage primary-side switching in 300–400 VDC input offline SMPS for industrial power supplies.

IC Role / Device Role / Timing Role: Power switch in asymmetrical half-bridge or single-ended forward converter with active clamp.

Use Value: 450 V V_CEO and 75 W P_C support 100–200 W output without derating; R_jc = 1.65°C/W simplifies thermal design.

Inductive Load Driver

High-Voltage Relay Replacement

Use Scenario: Solid-state replacement for mechanical relays driving solenoids, valves, or transformers in HVAC and factory automation.

IC Role / Device Role / Timing Role: Single-pole, high-voltage switching element with integrated flyback path for inductive kick suppression.

Use Value: Built-in diode handles >2 A flyback currents; t_F ≤ 200 ns ensures fast turn-off for precise duty-cycle control.

Use Scenario: Replacing electromechanical relays in 240 VAC motor starter circuits and lighting control panels.

IC Role / Device Role / Timing Role: Voltage-rated switching element with galvanic isolation via heatsink mounting and creepage-compliant TO-220 footprint.

Use Value: 1000 V V_CBO withstands surge transients per IEC 61000-4-5; TO-220-3LD allows direct PCB mount with screw terminal compatibility.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ST13007D	V_CEO = 400 V, I_C = 8 A, R_jc = 1.5°C/W, no integrated diode	Requires external flyback diode; higher current rating but lower voltage margin	Select when higher continuous current (8 A) is prioritized over integrated diode and 450 V rating.
BU508AF	V_CEO = 1500 V, I_C = 12 A, TO-3P package, no integrated diode	Larger footprint, higher voltage headroom, no built-in diode - needs external protection network	Choose for ultra-high-voltage applications (>600 V bus) where board space permits TO-3P and external diode integration.

Compared with ST13007D and BU508AF, the KSC5338D uniquely combines 450 V rating, integrated diode, and TO-220-3LD packaging - enabling compact, cost-optimized ballast and SMPS designs without external diode routing or thermal interface complexity.

Availability

KSC5338D is available at Aetrix Electronics and suitable for electronic ballast control, AC-DC SMPS half-bridge converters, and high-voltage relay replacement applications requiring stable component supply, long-lifecycle availability, and RoHS-compliant sourcing.

Supply support for KSC5338D 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT markets.

The KSC5338D belongs to onsemi's high-voltage bipolar power transistor product line, designed specifically for robust switching in electronic lighting ballasts, industrial motor controls, and offline power conversion systems.

FAQ

What is the maximum junction temperature specification for the KSC5338D?

The KSC5338D has a maximum junction temperature (T_J) rating of 150°C, as defined in its Absolute Maximum Ratings table. This limit must not be exceeded during operation, and thermal design must ensure that actual junction temperature remains below 150°C under worst-case ambient and power dissipation conditions. The KSC5338D's R_jc = 1.65°C/W and R_ja = 62.5°C/W values guide heatsink selection and PCB copper area requirements to maintain safe operation of the KSC5338D.

Does the KSC5338D have a built-in diode, and how is it connected?

Yes, the KSC5338D integrates a built-in free-wheeling diode connected between emitter and collector (anode to emitter, cathode to collector). This diode is monolithically fabricated within the same die and shares the same thermal environment as the transistor. Its forward voltage is 0.86–0.95 V at 1–2 A, and it supports inductive energy recirculation without external components - a key enabler for compact electronic ballast and SMPS designs using the KSC5338D.

What is the typical storage time (t_STG) of the KSC5338D under inductive load conditions?

Under inductive load switching with V_Z = 300 V, L_C = 200 μH, and I_C = 2 A, the KSC5338D exhibits a typical storage time (t_STG) of 1.95–2.25 μs at T_A = 25°C, increasing to up to 2.9 μs at 125°C. These values are measured with I_B1 = 400 mA and I_B2 = −0.4 A drive, and directly impact minimum off-time in fixed-frequency ballast controllers - a critical parameter for reliable operation of the KSC5338D in resonant lighting applications.

Can the KSC5338D be used in parallel configurations for higher current handling?

No, the KSC5338D is not recommended for parallel operation due to positive temperature coefficient of V_CE(sat) and non-uniform current sharing characteristics inherent to bipolar transistors. Its h_FE variation (6–25 at I_C = 2 A) and thermal coupling limitations make forced current balancing impractical. For higher current requirements, select a single higher-rated device such as the BU508AF or redesign the topology - do not attempt parallel use of the KSC5338D.

Is the KSC5338D pin-compatible with other TO-220 NPN transistors like the MJE13009?

No, the KSC5338D is not pin-compatible with MJE13009 or similar TO-220 NPN transistors. While both use TO-220-3LD packages, the KSC5338D pinout is Base–Collector–Emitter (1–2–3), whereas MJE13009 uses Emitter–Base–Collector (1–2–3). Mounting the KSC5338D in a footprint designed for MJE13009 will result in incorrect circuit connections and immediate failure. Always verify pin assignment using the official KSC5338D marking diagram before PCB layout.

KSC5338D Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-220-3

Packaging:: Bulk

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 5 A

Voltage - Collector Emitter Breakdown (Max):: 450 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 200mA, 1A

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 6 @ 2A, 1V

Power - Max:: 75 W

Frequency - Transition:: 11MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220-3

KSC5338D FAQ

1.How can I place an order for KSC5338D through Aetrix?

Please submit a Request for Quotation (RFQ) for KSC5338D on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for KSC5338D reliable?

The price and inventory of KSC5338D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC5338D is usually 5 days.

3.What payment methods are accepted for KSC5338D?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC5338D transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSC5338D?

KSC5338D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSC5338D order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for KSC5338D?

For technical support, including KSC5338D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC5338D requirements.

6.How does Aetrix verify that KSC5338D is sourced from the original manufacturer or authorized distributors?

All KSC5338D products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that KSC5338D meets industry standards.

7.What is the process for return or replacement of KSC5338D?

All KSC5338D units undergo pre-shipment inspection (PSI). If there is an issue with KSC5338D, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The KSC5338D part is unused and in its original packaging.

Return procedure for KSC5338D:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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