onsemi KSC1507Y

Overview

KSC1507Y from Fairchild Semiconductor is an NPN epitaxial silicon transistor designed for high-voltage chroma output stages in color TV systems, featuring VCEO = 300 V, fT ≥ 40 MHz, hFE = 120–240 (Class Y), PC = 15 W at TC = 25°C, and TO-220 package with base-collector-emitter pinout.

For engineers reviewing the KSC1507Y datasheet, pinout, applications, or equivalent options, this part supports high-voltage switching in analog video signal paths where breakdown voltage margin, gain-bandwidth stability, and thermal robustness under sustained collector dissipation are critical selection criteria.

Technical Context

The KSC1507Y operates as a high-voltage NPN switching transistor optimized for chroma demodulation and output amplification in legacy CRT-based color television receivers. Its 300 V VCEO and 300 V VCBO ratings enable safe operation across flyback-derived B+ rails and chroma trap circuits exposed to transient spikes.

With fT = 40–80 MHz and Cob = 4 pF at VCB = 50 V, the device maintains sufficient bandwidth for ~3.58 MHz chroma subcarrier handling while minimizing parasitic capacitance-induced phase shift. The hFE classification Y (120–240) ensures consistent current gain across production lots under VCE = 10 V, IC = 10 mA bias conditions.

Key Specifications

Pinout & Package

Package: TO-220 (standard 3-lead, through-hole, insulated tab). Dimensions per Fairchild Rev. A3: 15.90 mm × 10.08 mm × 18.95 mm max, mounting hole ø3.60 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KSC1507Y, MJD127G offers much higher hFE but insufficient voltage rating for CRT chroma output, while KSC1845Y provides superior RF performance and identical mechanical fit-making it the preferred upgrade path for legacy service replacements demanding enhanced signal integrity.

Availability

KSC1507Y is available at Aetrix Electronics and suitable for color TV repair, analog video equipment refurbishment, and industrial CRT-based instrumentation requiring stable component supply with long-lifecycle traceability.

Supply support for KSC1507Y 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 semiconductor company specializing in power discrete devices, analog ICs, and optoelectronics before its acquisition by ON Semiconductor in 2016.

The KSC1507Y belongs to Fairchild's high-voltage bipolar transistor family engineered specifically for analog video signal chain applications in consumer CRT television systems.

FAQ

What is the maximum collector current rating for KSC1507Y?

The KSC1507Y has an absolute maximum collector current (IC) rating of 0.2 mA under specified test conditions-but this reflects leakage limits, not operational capability. In actual circuit use, the device reliably handles pulsed or continuous collector currents up to 200 mA when operated within its SOA envelope and with proper heatsinking. Always verify operating point against the Safe Operating Area curves in the KSC1507Y datasheet.

Is KSC1507Y pin-compatible with other TO-220 NPN transistors?

Yes, the KSC1507Y uses standard TO-220 pinout: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter. This matches industry-standard TO-220 NPN orientation, enabling mechanical compatibility with sockets and PCB footprints designed for similar devices like MJE13009 or TIP41C-though electrical parameters (especially VCEO and fT) must be verified per application.

Does KSC1507Y require a heatsink in typical color TV chroma output use?

Yes, the KSC1507Y dissipates up to 15 W at TC = 25°C, but chroma output stages often operate near 5–10 W continuously. Without a heatsink, junction temperature rises rapidly beyond safe limits. A minimum 2.5°C/W aluminum heatsink is recommended for sustained operation; thermal interface material and mounting torque must comply with Fairchild's TO-220 mechanical guidelines to ensure reliability of the KSC1507Y.

What does the 'Y' suffix indicate in KSC1507Y?

The 'Y' suffix in KSC1507Y denotes the hFE gain bin: 120–240 at VCE = 10 V and IC = 10 mA. Fairchild used R (40–80), O (70–140), and Y (120–240) classifications to group units by DC current gain. This binning allows designers to select KSC1507Y when precise, repeatable base drive characteristics are needed-critical for consistent chroma output amplitude across mass-produced TV sets.

Can KSC1507Y be used in modern LCD or LED TV designs?

No-the KSC1507Y is functionally obsolete for modern digital video architectures. It was engineered for analog chroma processing in CRT TVs with 3.58 MHz subcarriers and high-voltage B+ rails. LCD/LED TVs use digital video processors, DC-DC converters, and low-voltage logic interfaces; substituting KSC1507Y would introduce unnecessary voltage overhead, thermal complexity, and no functional benefit. Use only for legacy CRT repair or compatible analog video systems.