onsemi KSC1507R

Overview

KSC1507R 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 = 40–80 (R-class), PC = 15 W at TC = 25°C, and TO-220 package with base-collector-emitter pinout.

For engineers reviewing the KSC1507R datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, thermal derating behavior, saturation voltage under defined drive conditions, output capacitance at 50 V, and confirmed use in analog video signal amplification where high breakdown voltage and moderate RF gain are required.

Technical Context

This device operates as a linear switching amplifier in high-voltage analog video circuits, with guaranteed BVCEO = 300 V at IC = 10 mA and ICBO ≤ 100 µA at VCB = 200 V. Its fT range of 40–80 MHz supports chroma signal bandwidth requirements without requiring external neutralization.

VCE(sat) = 2.0 V at IC = 50 mA / IB = 5 mA confirms usable saturation performance in quasi-linear output stages, while Cob = 4 pF at VCB = 50 V enables predictable high-frequency roll-off in tuned collector loads.

Key Specifications

Pinout & Package

Package: TO-220, 3-lead, through-hole, insulated tab, standard outline per Fairchild Rev. A3 (2002). Mounting hole ø3.60 mm, body height 18.95 mm max, lead pitch 2.54 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with KSC1507R, the 2SC4027 offers lower cost but sacrifices 50 V breakdown safety margin, while the KSC1845 provides superior fT and hFE spread control-making it better suited for precision chroma amplification where signal integrity is critical.

Availability

KSC1507R is available at Aetrix Electronics and suitable for color TV repair, CRT monitor refurbishment, analog video signal conditioning, and legacy broadcast equipment maintenance requiring stable component supply and long-lifecycle support.

Supply support for KSC1507R 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 management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The KSC1507R belongs to Fairchild's legacy high-voltage bipolar transistor family, engineered specifically for analog video output stages in consumer CRT-based television and display systems.

FAQ

What is the guaranteed minimum fT for KSC1507R?

The KSC1507R has a guaranteed minimum current gain bandwidth product (fT) of 40 MHz at VCE = 30 V and IC = 10 mA, as specified in the Fairchild Rev. A3 datasheet. This value ensures sufficient small-signal gain at chroma subcarrier frequencies with design margin. The typical fT is 80 MHz, but system-level timing analysis must use the 40 MHz minimum for worst-case verification. KSC1507R maintains this fT performance across its rated junction temperature range.

Is KSC1507R pin-compatible with other TO-220 NPN transistors?

KSC1507R uses standard TO-220 pinout: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter. While physically compatible with most TO-220 sockets, electrical compatibility depends on VCEO, hFE, and fT requirements. Substituting without verifying these parameters may cause instability or breakdown. KSC1507R is not a drop-in replacement for devices with different gain bins or voltage ratings, even in identical packages.

What does the 'R' suffix indicate in KSC1507R?

The 'R' suffix in KSC1507R denotes the hFE classification bin: R-class devices have DC current gain (hFE) ranging from 40 to 80 at VCE = 10 V and IC = 10 mA. This binning ensures predictable biasing behavior in production assemblies. Other variants include 'O' (70–140) and 'Y' (120–240). KSC1507R is selected specifically for applications requiring moderate, tightly controlled gain rather than maximum amplification.

Can KSC1507R be used in switching power supplies?

KSC1507R is optimized for linear analog video amplification-not hard-switching SMPS topologies. Its VCE(sat) of 2.0 V at IC = 50 mA / IB = 5 mA and lack of specified switching times make it unsuitable for high-efficiency, high-frequency converters. While it can handle 300 V in blocking state, KSC1507R lacks fast recovery characteristics and low storage time needed for reliable PWM operation. Use dedicated switching transistors instead.

What is the maximum allowable case temperature for continuous operation of KSC1507R?

KSC1507R has a maximum junction temperature (TJ) of 150°C and a storage temperature range of –55°C to +150°C. Its power derating curve shows linear reduction from 15 W at TC = 25°C to zero at TC ≈ 115°C. For reliable continuous operation, keep case temperature below 100°C with appropriate heatsinking. Exceeding this risks accelerated parameter drift and reduced lifetime. KSC1507R thermal resistance (RθJC) is not explicitly published, but TO-220 packaging implies ~1.5°C/W with standard mica insulator and thermal compound.