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

onsemi KSC5504DTTU

Name: KSC5504DTTU
Brand: onsemi
SKU: KSC5504DTTU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KSC5504DTTU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: KSC5504DTTU.pdf

Description:: TRANS NPN 600V 4A TO-220-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

KSC5504DTTU from Fairchild Semiconductor is an NPN triple-diffused planar silicon power transistor designed for high-voltage, high-speed switching in electronic ballasts and inductive load circuits. It features 600 V V_CEO, 4 A DC collector current, built-in free-wheeling diode, and a wide safe operating area (SOA) with avalanche energy rating of 3 mJ. Its primary circuit role is as a main switch in resonant lamp control systems.

For engineers reviewing the KSC5504DTTU datasheet, pinout, applications, or equivalent options, this device is evaluated for high-reliability fluorescent lamp ballast designs requiring fast turn-off, low storage time variance, and robust thermal performance at junction temperatures up to 150°C.

Technical Context

The KSC5504DTTU employs a triple-diffused planar structure optimized for high-voltage blocking and fast switching dynamics. Its integrated free-wheeling diode enables self-contained inductive energy recirculation without external components, reducing system complexity in ballast topologies.

It delivers controlled dynamic saturation voltage (V_CE(DSAT)) under pulsed inductive loads - 3 V at 3 µs for 2 A/400 mA drive - and maintains stable h_FE across temperature (min 10 at 125°C, IC = 2 A), supporting predictable base drive design in thermally demanding environments.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	600 V - Sustains full mains-derived DC bus voltages in electronic ballasts without breakdown
I_C (DC)	4 A - Supports lamp currents up to 4 A in standard T5/T8 ballast designs
t_STG (25°C)	1.5–2.5 µs - Enables precise timing control in 20–60 kHz resonant inverters
R_θJC	1.65 °C/W - Allows 75 W dissipation with ≤124°C case-to-junction rise at 25°C ambient
E_AS	3 mJ - Absorbs inductive flyback energy during switching transitions without failure
f_T	11 MHz - Ensures sufficient gain-bandwidth for stable high-frequency base drive amplification
V_F (IF = 1 A)	0.83–1.3 V - Low forward drop minimizes conduction loss in integrated diode path

Pinout & Package

Package: TO-220 (3-pin, straight lead, insulated tab). Mounting surface is electrically isolated from collector (pin 2).

Pin/Terminal	Circuit Role	Design Meaning
1 (Base)	Control input	Receives base current to saturate or cut off the transistor; requires ≥0.4 A peak for full 2 A switching
2 (Collector)	Main power output	Connected to high-side DC bus; carries full lamp current and handles 600 V blocking
3 (Emitter)	Power return / reference	Serves as common emitter node; also connects cathode of internal free-wheeling diode

Key Features

Feature	Design Value
Integrated free-wheeling diode	Eliminates need for external diode in half-bridge ballast outputs, reducing BOM count and layout area
Wide SOA (Forward Bias)	Supports linear-mode operation during startup transients without second breakdown up to 100 V/2 A
Low t_STG variance	Storage time remains tightly bounded (±0.5 µs) across temperature and current, enabling consistent dead-time control
High avalanche ruggedness	Rated for 3 mJ single-pulse avalanche energy, protecting against inductive kickback in unclamped loads
TO-220 insulated package	Enables direct heatsink mounting without insulating pads while maintaining electrical isolation from collector

Applications

Electronic Ballast Control	Inductive Load Switching
Use Scenario: Driving resonant LC tank in T5/T8 fluorescent lamp ballasts operating at 20–60 kHz. IC Role / Device Role / Timing Role: Main high-side switching transistor in half-bridge topology; controls lamp current via PWM and zero-voltage switching. Use Value: Built-in diode and tight t_STG tolerance enable reliable soft-switching transitions and reduce EMI generation.	Use Scenario: Controlling solenoid valves or relay coils in industrial automation where inductive energy must be safely dissipated. IC Role / Device Role / Timing Role: High-voltage switch with integrated flyback path; replaces discrete transistor + diode pair. Use Value: Avalanche-rated 3 mJ capability and 600 V V_CEO allow direct connection to 400 V DC bus without snubber networks.
UPS Inverter Stage	DC Motor Commutation
Use Scenario: Half-bridge leg in offline UPS inverters converting 350–400 V DC bus to 50/60 Hz AC output. IC Role / Device Role / Timing Role: High-voltage switching element handling peak currents up to 4 A during overload conditions. Use Value: Wide SOA and 150°C max junction temperature support sustained operation under brownout or overload stress.	Use Scenario: Brushed DC motor H-bridge driver in power tools or HVAC blowers requiring 200–400 V operation. IC Role / Device Role / Timing Role: Low-storage-time switch enabling precise commutation timing and reduced brush arcing. Use Value: 1.5–2.5 µs t_STG at 25°C ensures minimal cross-conduction risk during direction reversal.

Electronic Ballast Control

Inductive Load Switching

Use Scenario: Driving resonant LC tank in T5/T8 fluorescent lamp ballasts operating at 20–60 kHz.

IC Role / Device Role / Timing Role: Main high-side switching transistor in half-bridge topology; controls lamp current via PWM and zero-voltage switching.

Use Value: Built-in diode and tight t_STG tolerance enable reliable soft-switching transitions and reduce EMI generation.

Use Scenario: Controlling solenoid valves or relay coils in industrial automation where inductive energy must be safely dissipated.

IC Role / Device Role / Timing Role: High-voltage switch with integrated flyback path; replaces discrete transistor + diode pair.

Use Value: Avalanche-rated 3 mJ capability and 600 V V_CEO allow direct connection to 400 V DC bus without snubber networks.

UPS Inverter Stage

DC Motor Commutation

Use Scenario: Half-bridge leg in offline UPS inverters converting 350–400 V DC bus to 50/60 Hz AC output.

IC Role / Device Role / Timing Role: High-voltage switching element handling peak currents up to 4 A during overload conditions.

Use Value: Wide SOA and 150°C max junction temperature support sustained operation under brownout or overload stress.

Use Scenario: Brushed DC motor H-bridge driver in power tools or HVAC blowers requiring 200–400 V operation.

IC Role / Device Role / Timing Role: Low-storage-time switch enabling precise commutation timing and reduced brush arcing.

Use Value: 1.5–2.5 µs t_STG at 25°C ensures minimal cross-conduction risk during direction reversal.

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	600 V V_CEO, 8 A I_C, no integrated diode, TO-220FP package	Requires external flyback diode; higher current rating suits larger ballasts but increases drive complexity	Select when higher peak current headroom is needed and board space allows external diode placement
BU508A	1000 V V_CEO, 15 A I_C, no integrated diode, TO-3P package	Higher voltage margin for 600 V AC-input designs; larger thermal mass but no diode integration	Choose for legacy 1000 V-class ballasts where diode is already discrete and mechanical footprint is not constrained

Compared with ST13007D and BU508A, the KSC5504DTTU provides unique value through its monolithic free-wheeling diode, tighter storage time control, and TO-220 insulated package - simplifying design, reducing component count, and improving thermal reliability in compact electronic ballast modules.

Availability

KSC5504DTTU is available at Aetrix Electronics and suitable for electronic ballast control, inductive load switching, UPS inverter stages, and DC motor commutation requiring stable component supply and long-term industrial availability.

Supply support for KSC5504DTTU 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 analog and power semiconductor manufacturer, acquired by ON Semiconductor in 2016; its legacy power transistor portfolio remains widely deployed in industrial lighting and power conversion.

The KSC5504DTTU belongs to Fairchild's high-voltage NPN transistor family engineered specifically for electronic ballast and resonant switching applications - emphasizing ruggedness, timing consistency, and integrated protection features.

FAQ

What is the maximum junction temperature rating for the KSC5504DTTU?

The KSC5504DTTU has a maximum junction temperature (T_J) of 150°C, verified per Absolute Maximum Ratings in the original Fairchild datasheet. This rating enables continuous operation in enclosed ballast housings with limited airflow, provided thermal resistance from junction to case (R_θJC = 1.65°C/W) is respected in heatsink design. The KSC5504DTTU must not exceed this limit to maintain reliability and SOA integrity.

Does the KSC5504DTTU include an integrated diode, and what is its forward voltage?

Yes, the KSC5504DTTU integrates a free-wheeling diode between collector and emitter. Its forward voltage (V_F) is 0.83–1.3 V at I_F = 1 A and 25°C, rising to 0.8–1.5 V at 125°C depending on current. This diode eliminates the need for an external flyback component in half-bridge ballast outputs, and the KSC5504DTTU's diode parameters are fully characterized in the "Electrical Characteristics" section of the datasheet.

What is the storage time (t_STG) specification for the KSC5504DTTU at 125°C?

At 125°C, the KSC5504DTTU exhibits a storage time (t_STG) of 1.7–3.1 µs under resistive load conditions (I_C = 2 A, I_B1 = 0.4 A, I_B2 = 0.4 A), and 2.2–4.2 µs under inductive load conditions (same drive, V_Z = 300 V, L_C = 200 µH). This tightly bounded t_STG range supports precise dead-time control in high-frequency ballast drivers, and the KSC5504DTTU's consistency across temperature is explicitly documented in the switching characteristics table.

Is the KSC5504DTTU pin-compatible with the KSC5504D variant?

Yes, the KSC5504DTTU and KSC5504D share identical pinout (Base–Collector–Emitter), package outline (TO-220), and terminal assignments. Both variants use the same die and bonding configuration; the "TTU" suffix denotes tape-and-reel packaging for automated assembly, while "D" indicates tube packaging. All electrical, thermal, and switching specifications for the KSC5504DTTU match those published for the KSC5504D in the June 2001 Fairchild datasheet.

What is the avalanche energy rating of the KSC5504DTTU, and how is it tested?

The KSC5504DTTU is rated for 3 mJ of single-pulse avalanche energy (E_AS) at T_J = 25°C, measured using standardized pulse testing with defined voltage/current waveforms and thermal conditions. This rating confirms the device can safely absorb inductive flyback energy without degradation during transient overvoltage events, and the KSC5504DTTU's E_AS value is specified in the Absolute Maximum Ratings table alongside test methodology notes.

KSC5504DTTU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 4 A

Voltage - Collector Emitter Breakdown (Max):: 600 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 400mA, 2A

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 4 @ 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

KSC5504DTTU FAQ

1.How can I place an order for KSC5504DTTU through Aetrix?

Please submit a Request for Quotation (RFQ) for KSC5504DTTU 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 KSC5504DTTU reliable?

The price and inventory of KSC5504DTTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC5504DTTU is usually 5 days.

3.What payment methods are accepted for KSC5504DTTU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC5504DTTU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSC5504DTTU?

KSC5504DTTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSC5504DTTU 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 KSC5504DTTU?

For technical support, including KSC5504DTTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC5504DTTU requirements.

6.How does Aetrix verify that KSC5504DTTU is sourced from the original manufacturer or authorized distributors?

All KSC5504DTTU 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 KSC5504DTTU meets industry standards.

7.What is the process for return or replacement of KSC5504DTTU?

All KSC5504DTTU units undergo pre-shipment inspection (PSI). If there is an issue with KSC5504DTTU, 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 KSC5504DTTU part is unused and in its original packaging.

Return procedure for KSC5504DTTU:

1.Submit a request within 90 days.

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

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