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onsemi KSC2688OSTU
- Part No.:
- KSC2688OSTU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
KSC2688OSTU.pdf
- Description:
- TRANS NPN 300V 0.2A TO-126
- Quantity:
- Payment:
- Shipping:
Inventory:3,057
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Product details
Overview
KSC2688OSTU from Fairchild Semiconductor is an NPN epitaxial silicon transistor designed for high-voltage video output stages in color TV systems, featuring VCEO = 300 V, IC = 200 mA, PC = 10 W (TC = 25°C), and fT = 50–80 MHz.
For engineers reviewing the KSC2688OSTU datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin for CRT deflection circuits, saturation voltage under 50 mA drive, thermal derating at elevated case temperatures, and hFE classification consistency across R/O/Y/G bins.
Technical Context
The KSC2688OSTU operates as a medium-power, high-voltage NPN switching transistor with a TO-126 package enabling direct heatsink mounting. Its 300 V VCEO and 10 W power dissipation at TC = 25°C support sustained operation in chroma and video output amplifier stages where transient overvoltage and thermal cycling are common.
With hFE ranging 40–250 (depending on bin), VCE(sat) ≤ 1.5 V at IC = 50 mA/IB = 5 mA, and fT ≥ 50 MHz, the device balances gain, speed, and ruggedness for analog video signal amplification without requiring active bias compensation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 300 V - Withstands flyback-induced collector spikes in CRT video output circuits |
| IC | 200 mA - Supports peak current demands of chroma driver loads |
| PC (TC = 25°C) | 10 W - Enables high-power dissipation when mounted to heatsink |
| fT | 50–80 MHz - Sufficient bandwidth for baseband video (0–5 MHz) with margin |
| VCE(sat) | ≤1.5 V @ IC=50 mA/IB=5 mA - Minimizes conduction loss and self-heating |
| hFE range | 40–250 - Binned (R/O/Y/G) for consistent gain matching in production sets |
| Cre | 3 pF @ VCB=30 V - Low feedback capacitance preserves high-frequency stability |
Pinout & Package
TO-126 plastic power package with integral metal tab for mechanical mounting and thermal conduction. Pin 1 = Emitter, Pin 2 = Collector (tab-connected), Pin 3 = Base.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current sink terminal | Connected to ground or low-impedance return path in common-emitter video amps |
| 2 (Collector) | High-voltage output node | Electrically and thermally tied to metal tab; requires isolation washer when heatsinked |
| 3 (Base) | Control input | Receives drive current from preceding stage; low input impedance due to hFE-dependent loading |
Key Features
| Feature | Design Value |
|---|---|
| High VCEO rating | 300 V enables safe operation in CRT horizontal deflection and chroma output with 2× voltage margin |
| Thermal robustness | 150°C max junction temperature and defined power derating curve allow reliable operation up to 125°C case temp |
| Gain binning | R/O/Y/G hFE classifications simplify circuit tuning and reduce production calibration steps |
| Low Cre | 3 pF minimizes Miller effect, supporting stable gain above 10 MHz in video amplifier configurations |
| TO-126 mechanical interface | Standardized footprint and tab geometry enable drop-in replacement and heatsink compatibility across legacy designs |
Applications
| Color TV Chroma Output | Color TV Video Output |
|---|---|
Use Scenario: Amplifying demodulated color-difference signals (I/Q or U/V) prior to matrixing and CRT drive. IC Role / Device Role / Timing Role: Medium-power NPN switch/amplifier operating in Class-A or AB mode with DC-coupled collector load. Use Value: 300 V VCEO withstands CRT anode voltage transients; 10 W dissipation sustains continuous output without thermal runaway. | Use Scenario: Final-stage amplification of composite video signal driving CRT cathode or grid. IC Role / Device Role / Timing Role: High-slew-rate emitter-follower or common-emitter buffer delivering 1–2 Vpp into 75 Ω load. Use Value: 50–80 MHz fT ensures flat response across 0–5 MHz video bandwidth; low VCE(sat) maintains black-level accuracy. |
| Monitor Video Amplifier | Legacy Broadcast Equipment |
Use Scenario: RGB video line drivers in analog computer monitors and industrial display terminals. IC Role / Device Role / Timing Role: Single-ended output stage with fixed bias network and emitter degeneration resistor. Use Value: hFE binning (Y/G) allows precise gain setting; TO-126 tab enables direct heatsinking on metal chassis. | Use Scenario: Signal conditioning in aging broadcast studio gear requiring field-replaceable discrete transistors. IC Role / Device Role / Timing Role: Replacement part for obsolete video output transistors in maintenance spares inventory. Use Value: Pin-compatible with legacy TO-126 footprints; identical VCEO, IC, and thermal specs ensure no redesign needed. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN high-voltage video amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD2955G | VCEO = 80 V, IC = 12 A, PC = 115 W - lower voltage, higher current, larger TO-220 package | Designed for power supply pass transistors, not video signal integrity | Select only if redesigning for lower-voltage, higher-current DC applications; not suitable for CRT video output |
| KSC2688S | Same die, same electrical specs, TO-126 package - differs only in marking and tape/reel packaging | No functional difference; used interchangeably in manufacturing | KSC2688S is a valid alternate for KSC2688OSTU in new builds or replacements where packaging format is flexible |
Compared with MJD2955G, KSC2688OSTU provides essential 300 V breakdown for CRT flyback immunity but lower current capability; versus KSC2688S, it offers identical performance with standardized OEM tape-and-reel delivery for automated assembly.
Availability
KSC2688OSTU is available at Aetrix Electronics and suitable for color TV repair, analog video equipment refurbishment, and legacy broadcast hardware maintenance requiring stable component supply and long-term obsolescence mitigation.
Supply support for KSC2688OSTU 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 leading designer of discrete semiconductors and power management ICs, acquired by ON Semiconductor in 2016; known for rugged, high-reliability bipolar transistors.
The KSC2688OSTU belongs to Fairchild's legacy high-voltage NPN transistor family, engineered specifically for analog video output stages in consumer CRT-based television and monitor systems.
FAQ
What is the maximum collector-emitter voltage rating for KSC2688OSTU?
The KSC2688OSTU has a guaranteed minimum VCEO of 300 V at IC = 5 mA and TC = 25°C. This rating is critical for safe operation in CRT video output circuits where flyback transients exceed 200 V. Derating applies above 25°C case temperature per the published power derating curve. The KSC2688OSTU must not be operated beyond this limit without external clamping or snubbing networks.
Does KSC2688OSTU have a built-in base-emitter resistor?
No, the KSC2688OSTU is a standard three-terminal NPN bipolar junction transistor with no integrated resistors. It requires external base biasing components - typically a voltage divider or current source - to establish proper Q-point in amplifier or switch configurations. This discrete design allows full flexibility in gain, speed, and thermal compensation tuning for each application.
What is the thermal resistance from junction to case (RθJC) for KSC2688OSTU?
The KSC2688OSTU datasheet does not specify RθJC directly, but its 10 W power dissipation rating at TC = 25°C implies an effective RθJC of approximately 12.5°C/W when mounted to a heatsink with low thermal interface resistance. Actual thermal performance depends on mounting pressure, thermal paste quality, and heatsink surface flatness - all critical for sustaining rated power in video output applications.
Is KSC2688OSTU RoHS compliant?
The original KSC2688OSTU was manufactured prior to RoHS enforcement and contains lead in the solderable terminations and die attach. It is classified as a legacy non-RoHS product. For RoHS-compliant alternatives, consult Aetrix Electronics' engineering support team - substitutions require validation of voltage, gain, and thermal behavior in the target circuit.
How is the hFE binning indicated on KSC2688OSTU packaging?
The KSC2688OSTU is marked with a color dot or letter code indicating its hFE bin: R (40–80), O (60–120), Y (100–200), or G (160–250). This marking appears on the package body adjacent to the part number. Binning ensures predictable DC gain in production assemblies, reducing need for post-manufacture trimming in color TV chroma circuits.
KSC2688OSTU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 200 mA
- Voltage - Collector Emitter Breakdown (Max):
- 300 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.5V @ 5mA, 50mA
- Current - Collector Cutoff (Max):
- 100µA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 60 @ 10mA, 10V
- Power - Max:
- 1.25 W
- Frequency - Transition:
- 80MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126
KSC2688OSTU FAQ
1.How can I place an order for KSC2688OSTU through Aetrix?
Please submit a Request for Quotation (RFQ) for KSC2688OSTU 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 KSC2688OSTU reliable?
The price and inventory of KSC2688OSTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC2688OSTU is usually 5 days.
3.What payment methods are accepted for KSC2688OSTU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC2688OSTU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSC2688OSTU?
KSC2688OSTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSC2688OSTU 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 KSC2688OSTU?
For technical support, including KSC2688OSTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC2688OSTU requirements.
6.How does Aetrix verify that KSC2688OSTU is sourced from the original manufacturer or authorized distributors?
All KSC2688OSTU 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 KSC2688OSTU meets industry standards.
7.What is the process for return or replacement of KSC2688OSTU?
All KSC2688OSTU units undergo pre-shipment inspection (PSI). If there is an issue with KSC2688OSTU, 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 KSC2688OSTU part is unused and in its original packaging.
Return procedure for KSC2688OSTU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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