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onsemi KSD401YTU
- Part No.:
- KSD401YTU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-220-3
- Datasheet:
-
KSD401YTU.pdf
- Description:
- TRANS NPN 150V 2A TO-220-3
- Quantity:
- Payment:
- Shipping:
Inventory:2,933
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Product details
Overview
KSD401YTU from ON Semiconductor (formerly Fairchild) is an NPN epitaxial silicon power transistor designed for TV vertical deflection output stages. It delivers 2 A collector current, 150 V collector-emitter breakdown voltage, and 25 W collector dissipation at TC=25°C in a TO-220 package, enabling high-voltage switching in CRT display horizontal/vertical scan circuits.
For engineers reviewing the KSD401YTU datasheet, pinout, applications, or equivalent options, this device is selected for high-voltage linear/switching operation where DC current gain (hFE = 120–240), low saturation voltage (VCE(sat) = 1 V @ IC = 500 mA), and thermal robustness (TJ = 150°C) are critical in deflection yoke driver designs.
Technical Context
The KSD401YTU operates as a medium-power NPN bipolar junction transistor with fixed gain classification 'Y' (hFE = 120–240). Its safe operating area supports single-pulse and thermal-limited operation up to 25 W at 25°C case temperature, with derating above 25°C per the published power derating curve.
It features a 200 V collector-base breakdown rating (BVCBO), 5 V emitter-base limit (BVEBO), and 5 MHz current-gain bandwidth product (fT) under VCE = 10 V, IC = 0.4 A conditions - confirming suitability for quasi-resonant and linear sweep applications in analog video deflection systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCBO | 200 V - Withstands 200 V reverse bias between collector and base without breakdown, enabling use in high-voltage flyback and deflection circuits. |
| VCEO | 150 V - Sustains 150 V between collector and emitter at zero base current, defining maximum usable supply rail in vertical output stage. |
| IC | 2 A - Continuous collector current rating, supporting peak deflection yoke drive currents in CRT TVs. |
| PC (TC=25°C) | 25 W - Maximum power dissipation at 25°C case temperature; requires heatsinking for sustained operation above ambient. |
| hFE (Y-class) | 120–240 - Confirmed DC current gain range at VCE = 10 V, IC = 0.4 A, ensuring predictable base drive requirements. |
| VCE(sat) | 1 V @ IC = 500 mA, IB = 50 mA - Low saturation voltage minimizes conduction loss and self-heating during active switching. |
| fT | 5 MHz - Current-gain bandwidth product confirms usable frequency response up to several MHz for vertical scan linearity. |
Pinout & Package
Package: TO-220 (3-lead, straight lead, insulated tab). Dimensions conform to JEDEC TO-220AB standard with 15.90 mm height, 10.08 mm width, and 4.50 mm lead pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Left) | Base | Control terminal; accepts base current to drive transistor into saturation or active region; requires current-limiting resistor in series. |
| 2 (Center) | Collector | Main high-current output node; connected to deflection yoke and flyback transformer primary; electrically tied to metal tab. |
| 3 (Right) | Emitter | Current return path; typically grounded or connected to low-side sensing; provides reference for base-emitter bias. |
Key Features
| Feature | Design Value |
|---|---|
| High VCBO rating | 200 V enables reliable operation in CRT flyback and vertical deflection circuits with high inductive kickback. |
| Complementary pairing | Designed as NPN complement to KSB546 PNP transistor for push-pull vertical output stages. |
| Thermal stability | Junction temperature rating of 150°C supports operation in enclosed TV chassis with limited airflow. |
| Low VCE(sat) | 1 V saturation voltage reduces power loss and improves efficiency in linear sweep applications. |
Applications
| TV Vertical Deflection Output | CRT Monitor Sweep Driver |
|---|---|
Use Scenario: Driving vertical deflection yoke in analog television receivers requiring precise 50/60 Hz sawtooth current waveform. IC Role / Device Role / Timing Role: NPN power switch amplifying base-driven current to generate yoke magnetic field; operates in linear and saturated modes across scan cycle. Use Value: 150 V VCEO and 2 A IC support full vertical scan energy delivery; 120–240 hFE ensures stable gain across production lots. | Use Scenario: Generating vertical sweep current in professional CRT monitors with tight linearity and thermal stability requirements. IC Role / Device Role / Timing Role: High-voltage, medium-current output stage transistor in discrete vertical oscillator-amplifier chain. Use Value: 25 W PC rating with TO-220 package allows direct mounting to chassis heatsink; 5 MHz fT preserves waveform fidelity at scan frequencies. |
| Video Projector Vertical Scan | Legacy Broadcast Equipment |
Use Scenario: Vertical scanning in CRT-based video projectors where compact yoke drive and low thermal drift are essential. IC Role / Device Role / Timing Role: Linear-mode output transistor controlling yoke current with feedback-stabilized base bias. Use Value: 1 V VCE(sat) minimizes conduction loss during retrace; 150°C TJ rating sustains performance under continuous duty. | Use Scenario: Signal generation and amplification in legacy broadcast test equipment using analog CRT displays. IC Role / Device Role / Timing Role: Deflection stage switch in calibrated timing generators and waveform analyzers with CRT front panels. Use Value: Complementarity with KSB546 enables matched push-pull design; TO-220 mechanical robustness suits rack-mounted industrial enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN high-voltage power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD44H11 | Higher VCEO (200 V), higher hFE (75–220), same TO-220 package but higher PC (30 W). | Used in audio output and SMPS; less common in legacy TV deflection due to different gain binning. | Preferred when higher voltage margin or improved thermal headroom is required; verify base drive compatibility. |
| KSC2690A | Lower VCEO (120 V), lower PC (20 W), same hFE range (120–240), TO-220 package. | Targeted at lower-voltage horizontal deflection and general-purpose switching. | Only suitable for reduced-swing vertical applications; not recommended for full 150 V VCEO requirement. |
Compared with KSD401YTU, MJD44H11 offers greater voltage and power headroom but may require recalibration of base drive, while KSC2690A sacrifices critical voltage rating and thermal capacity - making KSD401YTU the optimal match for legacy CRT vertical deflection where 150 V VCEO and 25 W dissipation are non-negotiable.
Availability
KSD401YTU is available at Aetrix Electronics and suitable for CRT television repair, analog video equipment maintenance, and legacy broadcast hardware refurbishment requiring stable component supply and long-term obsolescence mitigation.
Supply support for KSD401YTU 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 power management, analog, and sensor technologies for automotive, industrial, and consumer markets.
The KSD401YTU belongs to Fairchild's legacy TV deflection transistor family, engineered specifically for high-reliability, high-voltage linear switching in analog CRT display systems.
FAQ
What is the pin configuration of the KSD401YTU?
The KSD401YTU uses a standard TO-220 package with pin 1 = Base, pin 2 = Collector (tab-connected), and pin 3 = Emitter. This configuration is confirmed in the Fairchild Rev. B datasheet and matches JEDEC TO-220AB mechanical drawings. The metal tab is electrically connected to the collector, requiring insulation when mounted to grounded heatsinks.
Is the KSD401YTU RoHS compliant?
The KSD401YTU was manufactured prior to RoHS enforcement and is not RoHS compliant. It contains lead in solder and packaging materials per pre-2006 Fairchild specifications. For RoHS-compliant alternatives, consult ON Semiconductor's modern equivalents such as the MJD44H11, which carries active RoHS certification.
What is the hFE classification for KSD401YTU?
The KSD401YTU is classified as 'Y' grade, with a guaranteed DC current gain (hFE) range of 120–240 at VCE = 10 V and IC = 0.4 A. This classification is explicitly stated in the Fairchild datasheet's hFE Classification table and distinguishes it from 'G' grade (200–400) variants of the same family.
Can KSD401YTU replace KSD401Y in circuit designs?
Yes - KSD401YTU is a direct replacement for KSD401Y. Both share identical electrical specifications, TO-220 package, pinout, and 'Y' hFE classification. The 'TU' suffix denotes tape-and-reel packaging for automated assembly; the die and performance are functionally identical to the tube-packaged KSD401Y.
What thermal derating applies to KSD401YTU above 25°C?
KSD401YTU must be derated linearly above TC = 25°C at 0.2 W/°C, as shown in Figure 6 of the Fairchild datasheet. At 75°C case temperature, maximum allowable power drops to 15 W; at 125°C, it falls to 5 W. Adequate heatsinking is mandatory to maintain safe junction temperature below 150°C.
KSD401YTU 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):
- 2 A
- Voltage - Collector Emitter Breakdown (Max):
- 150 V
- Vce Saturation (Max) @ Ib, Ic:
- 1V @ 50mA, 500mA
- Current - Collector Cutoff (Max):
- 50µA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 120 @ 400mA, 10V
- Power - Max:
- 25 W
- Frequency - Transition:
- 5MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-3
KSD401YTU FAQ
1.How can I place an order for KSD401YTU through Aetrix?
Please submit a Request for Quotation (RFQ) for KSD401YTU 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 KSD401YTU reliable?
The price and inventory of KSD401YTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSD401YTU is usually 5 days.
3.What payment methods are accepted for KSD401YTU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSD401YTU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSD401YTU?
KSD401YTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSD401YTU 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 KSD401YTU?
For technical support, including KSD401YTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSD401YTU requirements.
6.How does Aetrix verify that KSD401YTU is sourced from the original manufacturer or authorized distributors?
All KSD401YTU 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 KSD401YTU meets industry standards.
7.What is the process for return or replacement of KSD401YTU?
All KSD401YTU units undergo pre-shipment inspection (PSI). If there is an issue with KSD401YTU, 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 KSD401YTU part is unused and in its original packaging.
Return procedure for KSD401YTU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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