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onsemi KSC2258AS
- Part No.:
- KSC2258AS
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
KSC2258AS.pdf
- Description:
- TRANS NPN 300V 0.1A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,740
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Product details
Overview
KSC2258AS from Fairchild Semiconductor is an NPN epitaxial silicon transistor designed for high-voltage general amplification and TV video output stages, featuring VCEO = 300 V, IC = 100 mA DC, fT = 100 MHz, Cob = 4.5 pF max, and TO-126 package with emitter-collector-base pinout.
For engineers reviewing the KSC2258AS datasheet, pinout, applications, or equivalent options, this device serves as a high-BVCEO discrete amplifier in analog video signal chains, CRT deflection drivers, and industrial HV switching where low saturation voltage and stable gain at 50 V bias are required.
Technical Context
The KSC2258AS operates as a single NPN bipolar junction transistor optimized for high-voltage linear amplification, not switching-only use. Its design supports VCE up to 300 V with hFE ≥ 30 at IC = 5 mA and VCE = 50 V, and maintains fT = 100 MHz under VCE = 10 V, IC = 10 mA conditions.
Thermal performance is defined by PC = 4 W at TC = 25°C and derates linearly above 25°C case temperature, with TJ limited to 150°C. Output capacitance Cob is specified at 3–4.5 pF (VCB = 50 V, f = 1 MHz), supporting stable high-frequency video gain without excessive phase shift.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCBO | 300 V - Enables safe operation with collector-base reverse bias up to 300 V, critical for CRT anode drive and flyback transformer interfaces. |
| VCEO | 300 V - Supports full-swing amplification of high-voltage video signals without breakdown in TV output stages. |
| hFE2 | ≥30 at VCE = 50 V, IC = 5 mA - Ensures usable current gain under high-voltage bias, unlike low-VCE test conditions. |
| fT | 100 MHz - Provides sufficient bandwidth for composite video (up to ~5 MHz) with margin for transient response and stability. |
| Cob | 4.5 pF max at VCB = 50 V - Limits Miller effect in high-gain, high-voltage configurations to maintain phase margin. |
| VCE(sat) | 1.2 V at IC = 50 mA, IB = 5 mA - Delivers low conduction loss in quasi-linear output stages, reducing thermal stress. |
| PC | 4 W at TC = 25°C - Allows direct mounting on heatsinks for sustained power dissipation in video driver circuits. |
Pinout & Package
Package: TO-126 - Three-lead plastic power package with integral metal tab for heatsinking; dimensions 16.10 × 13.06 × 4.2 mm (L × W × H), lead pitch 2.28 mm, tab electrically connected to collector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current sink terminal | Reference node for base drive; polarity defines NPN operation-must be at lowest potential in circuit. |
| 2 (Collector) | High-voltage output terminal | Connected to heatsink tab; carries full load current and high-voltage swing-requires isolation from PCB ground plane. |
| 3 (Base) | Control input terminal | Receives forward-biased current to modulate collector-emitter conduction; requires series resistor to limit IB per hFE requirements. |
Key Features
| Feature | Design Value |
|---|---|
| High BVCEO rating | 300 V enables direct interface with CRT anode supplies and flyback secondary windings without external snubbing. |
| Stable hFE at high VCE | hFE ≥ 30 at VCE = 50 V ensures predictable gain in video output amplifiers operating near half-rail voltage. |
| Low VCE(sat) | 1.2 V at rated IC reduces power loss and self-heating in continuous-output video driver applications. |
| Controlled Cob | 4.5 pF max minimizes feedback capacitance in high-gain common-emitter stages, preserving bandwidth and stability. |
| TO-126 thermal design | Integral collector-tab heatsinking supports 4 W dissipation with minimal thermal resistance when mounted to chassis or heatsink. |
Applications
| TV Video Output Amplifier | CRT Deflection Driver |
|---|---|
Use Scenario: Amplifying composite video signals prior to CRT grid or cathode drive in analog television receivers. IC Role / Device Role / Timing Role: Linear NPN amplifier operating in Class-A or AB mode, delivering 1–2 Vpp into 75 Ω load with minimal distortion. Use Value: 300 V VCEO withstands CRT anode flyback transients while maintaining linearity across 0–5 MHz bandwidth. | Use Scenario: Driving horizontal or vertical deflection yoke windings in CRT monitors requiring high-voltage, medium-current pulses. IC Role / Device Role / Timing Role: High-voltage switch-amplifier handling repetitive 15.734 kHz (H) or 60 Hz (V) sawtooth currents up to 100 mA peak. Use Value: 4 W power dissipation and low VCE(sat) reduce thermal cycling stress during sustained deflection operation. |
| Industrial HV Signal Buffer | Analog Video Distribution Amplifier |
Use Scenario: Isolating and boosting high-voltage sensor outputs (e.g., photomultiplier, ion chamber) in test equipment. IC Role / Device Role / Timing Role: Emitter-follower or common-emitter buffer stage translating low-current signals to higher drive capability at 200–300 V swing. Use Value: 300 V VCBO prevents breakdown during open-circuit or capacitive-load transients in instrumentation front-ends. | Use Scenario: Splitting and re-driving composite video signals to multiple displays or recording devices without degradation. IC Role / Device Role / Timing Role: Unity-gain or slight-gain buffer with matched impedance and low phase error across baseband video spectrum. Use Value: 100 MHz fT and 4.5 pF Cob ensure flat group delay and minimal overshoot in multi-path distribution networks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage NPN amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD2258A | Same VCEO = 300 V, but TO-252 (DPAK) package; hFE min = 40 at IC = 40 mA, slightly higher Cob = 5.5 pF. | Better suited for surface-mount PCBs with automated assembly; less effective heatsinking than TO-126 tab. | Select MJD2258A only when SMT layout and thermal management via copper pour are prioritized over through-hole mechanical robustness. |
| KSC2383YTA | VCEO = 200 V (lower), hFE = 120 min at IC = 50 mA, fT = 120 MHz, TO-126 package identical. | Higher gain and speed but reduced voltage margin-unsuitable for CRT anode-related circuits above 200 V. | Choose KSC2383YTA only in lower-voltage video buffers where 200 V headroom suffices and higher fT improves transient fidelity. |
Compared with MJD2258A and KSC2383YTA, the KSC2258AS uniquely balances 300 V ruggedness, TO-126 thermal reliability, and 100 MHz bandwidth-making it irreplaceable in legacy CRT video output designs requiring proven high-voltage linearity and serviceability.
Availability
KSC2258AS is available at Aetrix Electronics and suitable for CRT television repair, analog video equipment maintenance, and industrial high-voltage signal conditioning requiring stable component supply and long-term obsolescence mitigation.
Supply support for KSC2258AS 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 designer of analog and discrete semiconductors, acquired by ON Semiconductor in 2016; known for high-reliability power transistors and legacy TV/video components.
The KSC2258AS belongs to Fairchild's high-voltage NPN transistor family engineered specifically for analog video output stages, CRT deflection, and industrial HV amplification where voltage margin and thermal stability outweigh digital-speed requirements.
FAQ
What is the maximum collector-emitter voltage rating for KSC2258AS?
The KSC2258AS has a guaranteed VCEO rating of 300 V at TC = 25°C, verified per Fairchild's Rev. A datasheet. This rating applies strictly under DC or pulse conditions with proper heatsinking; derating is required above 25°C case temperature per the published power derating curve. The KSC2258AS must not be operated beyond this limit to avoid avalanche failure or permanent degradation.
Is KSC2258AS pin-compatible with KSC2258?
Yes, the KSC2258AS shares identical TO-126 pinout (Emitter-Collector-Base) and mechanical footprint with KSC2258, but differs in absolute maximum ratings: KSC2258AS specifies VCEO = 300 V versus 250 V for KSC2258. Both use the same pin assignment and package outline, enabling direct replacement where voltage margin is acceptable.
What is the typical current gain (hFE) of KSC2258AS at high collector-emitter voltage?
The KSC2258AS delivers hFE ≥ 30 at VCE = 50 V and IC = 5 mA, as specified in the "Electrical Characteristics" table. This value reflects gain under high-voltage bias relevant to video output operation-not the higher hFE measured at low VCE. At VCE = 20 V and IC = 40 mA, hFE is ≥ 40, confirming usable gain across its intended operating range.
Can KSC2258AS be used in switching applications?
The KSC2258AS is characterized and optimized for linear amplification, not fast switching. While it can function as a switch, its 1.2 V VCE(sat) and 100 MHz fT do not indicate optimized switching speed or charge storage characteristics. For dedicated switching, Fairchild's MJD series or modern MOSFET alternatives offer superior efficiency and rise/fall times.
What thermal considerations apply when using KSC2258AS at full power dissipation?
At full 4 W dissipation, the KSC2258AS requires a heatsink capable of maintaining TC ≤ 25°C; junction temperature rises 150°C above case. Without forced cooling, ambient temperature must remain below 25°C, and PCB copper area around the collector tab must exceed 10 cm². Derating begins immediately above 25°C case temperature-e.g., at TC = 75°C, max PC drops to 2 W per the linear derating curve.
KSC2258AS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 300 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.2V @ 5mA, 50mA
- Current - Collector Cutoff (Max):
- -
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 40 @ 40mA, 20V
- Power - Max:
- 4 W
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126-3
KSC2258AS FAQ
1.How can I place an order for KSC2258AS through Aetrix?
Please submit a Request for Quotation (RFQ) for KSC2258AS 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 KSC2258AS reliable?
The price and inventory of KSC2258AS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC2258AS is usually 5 days.
3.What payment methods are accepted for KSC2258AS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC2258AS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSC2258AS?
KSC2258AS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSC2258AS 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 KSC2258AS?
For technical support, including KSC2258AS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC2258AS requirements.
6.How does Aetrix verify that KSC2258AS is sourced from the original manufacturer or authorized distributors?
All KSC2258AS 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 KSC2258AS meets industry standards.
7.What is the process for return or replacement of KSC2258AS?
All KSC2258AS units undergo pre-shipment inspection (PSI). If there is an issue with KSC2258AS, 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 KSC2258AS part is unused and in its original packaging.
Return procedure for KSC2258AS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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