onsemi KSC1674RTA

Overview

KSC1674RTA from ON Semiconductor is an NPN epitaxial silicon transistor designed for RF amplification and mixing in TV PIF and FM tuner applications, with a typical current gain bandwidth product (f_T) of 600 MHz, V_CEO = 20 V, I_C = 20 mA, and V_CE(sat) ≤ 0.3 V at I_C = 10 mA / I_B = 1 mA.

For engineers reviewing the KSC1674RTA datasheet, pinout, applications, or equivalent options, key selection criteria include its high-frequency f_T performance, low-noise figure (3.0–5.0 dB at 100 MHz), TO-92 package compatibility, h_FE classification (R/O/Y), and suitability for RF front-end signal conditioning where gain stability and low capacitance (C_ob = 1.2 pF) are critical.

Technical Context

The KSC1674RTA operates as a general-purpose RF amplifier transistor with optimized epitaxial base construction to support stable high-frequency gain up to 600 MHz. Its low output capacitance (C_ob = 1.2 pF at V_CB = 6 V) and fast collector-base time constant (12–15 ps) enable minimal phase distortion in oscillator and mixer stages.

It features a fixed h_FE classification range (R: 40–80, O: 70–140, Y: 120–240), defined per unit, and specified saturation behavior (V_CE(sat) ≤ 0.3 V) under standard bias conditions-supporting predictable switching and linear amplification in compact analog RF designs.

Key Specifications

Pinout & Package

Package: TO-92 (3-lead plastic through-hole), lead configuration: Emitter-Base-Collector (suffix "RTA" confirms standard pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN RF transistor applications.

Compared with 2SC3356(TE85L,F) and BC550C, the KSC1674RTA offers balanced f_T, noise, and TO-92 through-hole compatibility for cost-sensitive analog TV/FM receiver designs-where 600 MHz bandwidth and 1.2 pF C_ob meet legacy system requirements without over-specifying.

Availability

KSC1674RTA is available at Aetrix Electronics and suitable for TV PIF amplifiers, FM tuner RF amplifiers, mixer stages, and oscillator cores requiring stable component supply in legacy consumer electronics manufacturing and repair programs.

Supply support for KSC1674RTA 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 is a global semiconductor manufacturer specializing in power management, analog, sensor, and logic solutions for automotive, industrial, and consumer markets.

The KSC1674RTA belongs to ON Semiconductor's legacy RF transistor product line-originally developed by Fairchild-to address high-frequency analog signal conditioning in broadcast receiver systems.

FAQ

What is the pin configuration of the KSC1674RTA?

The KSC1674RTA uses a TO-92 package with standard pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector. This configuration is confirmed in the original Fairchild datasheet and maintained in ON Semiconductor's documentation. The "RTA" suffix explicitly denotes this E-B-C order, distinguishing it from center-collector variants. Always verify orientation using the flat side and lead-down view per JEDEC TO-92 standards before PCB layout.

Does the KSC1674RTA support FM tuner applications?

Yes, the KSC1674RTA is specifically qualified for FM tuner RF amplifier use, with a noise figure of 3.0–5.0 dB at 100 MHz and R_S = 50 Ω, plus f_T = 600 MHz (typ.) ensuring adequate gain margin across the 88–108 MHz band. Its low C_ob (1.2 pF) and stable h_FE classification support repeatable input matching and gain control-key for high-fidelity analog FM reception in consumer-grade tuners.

What h_FE classification does the KSC1674RTA have?

The KSC1674RTA is manufactured in three h_FE bins: R (40–80), O (70–140), and Y (120–240), with the specific classification marked on the device body. This binning allows design-in flexibility-e.g., Y-grade for high-gain IF stages, R-grade for stable oscillator biasing. The h_FE value is measured at V_CE = 6 V and I_C = 1 mA, and must be verified per unit during production testing for gain-critical applications.

Can the KSC1674RTA replace the KSC1674 in existing designs?

Yes, the KSC1674RTA is a direct replacement for the KSC1674, sharing identical electrical specifications, TO-92 package, and E-B-C pinout. The "RTA" suffix reflects Fairchild/ON Semiconductor's standardized nomenclature update (replacing underscores with dashes) and does not indicate functional or parametric change. No PCB or schematic modifications are needed when migrating from KSC1674 to KSC1674RTA.

What is the maximum junction temperature rating for the KSC1674RTA?

The KSC1674RTA has a maximum junction temperature (T_J) rating of 150°C, as specified in its Absolute Maximum Ratings table. This allows reliable operation in ambient temperatures up to ~125°C when mounted on standard FR-4 PCBs with moderate copper pour, provided power dissipation remains within the 250 mW limit. Derating is required above 25°C ambient per the thermal resistance curve in the datasheet.