onsemi KSC2786YTA

Overview

KSC2786YTA from Fairchild Semiconductor is an NPN epitaxial silicon transistor optimized for RF amplification in TV PIF and FM tuner front-ends, mixer, and oscillator stages. It delivers f_T = 600 MHz (typ), GPE = 22 dB at 100 MHz, V_CE(sat) = 0.3 V max at I_C = 10 mA/I_B = 1 mA, and h_FE = 120–240 (Y-class), housed in a TO-92S package.

For engineers reviewing the KSC2786YTA datasheet, pinout, applications, or equivalent options, key selection criteria include its high-frequency gain-bandwidth performance, low-noise figure (3.0–5.0 dB at 100 MHz), saturation voltage behavior, DC current gain classification, and TO-92S leadform compatibility with manual or wave-soldered RF board layouts.

Technical Context

The KSC2786YTA employs an epitaxial base structure to achieve high f_T and stable h_FE across its Y-class range (120–240). Its low C_ob = 1.2 pF and C_c·rbb' = 15 ps support wideband RF operation up to VHF/UHF bands without excessive phase shift or instability.

Designed for small-signal amplification, it operates with V_CE ≤ 20 V and I_C ≤ 20 mA, featuring low V_BE(on) = 0.72 V and tight V_CE(sat) spec (0.1–0.3 V) - enabling efficient biasing in Class-A or Class-C oscillator and amplifier topologies where thermal stability and gain linearity are critical.

Key Specifications

Pinout & Package

Package: TO-92S - 3-lead through-hole plastic package with 1.27 mm lead pitch, 3.72 mm body width, and 4.00 mm height; optimized for RF layout with short internal leads and low inductance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SC3356(TE85L,F) and BC550C, the KSC2786YTA offers balanced RF gain, noise, and saturation performance specifically binned and characterized for TV/FM tuner signal chains - whereas 2SC3356 targets higher frequencies with different mechanical fit, and BC550C lacks verified RF parameters entirely.

Availability

KSC2786YTA is available at Aetrix Electronics and suitable for TV PIF amplifiers, FM tuner RF front-ends, and discrete oscillator modules requiring stable component supply and consistent Y-class h_FE performance.

Supply support for KSC2786YTA 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 manufacturer specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The KSC2786YTA belongs to Fairchild's legacy RF transistor product line, engineered for high-frequency analog signal conditioning in broadcast receiver systems - emphasizing gain stability, low noise, and manufacturable TO-92S packaging.

FAQ

What is the hFE classification for KSC2786YTA?

The "Y" suffix in KSC2786YTA denotes the h_FE bin: 120–240 at V_CE = 6 V and I_C = 1 mA. This tight gain range ensures predictable biasing and gain uniformity in production TV and FM tuner modules, reducing calibration overhead. The KSC2786YTA data sheet explicitly lists Y-class as the highest gain bin among R (40–80) and O (70–140).

Does KSC2786YTA support operation at 100 MHz with usable gain?

Yes - the KSC2786YTA delivers GPE = 22 dB at 100 MHz and f_T = 600 MHz (typ), confirming robust small-signal gain well above that frequency. Its low C_ob = 1.2 pF and optimized epitaxial structure maintain phase stability in common-emitter amplifier configurations used in FM tuner RF stages. Measured y-parameter plots in the KSC2786YTA datasheet confirm usable g_fe > 10 mS at 100 MHz.

What is the maximum collector current rating for KSC2786YTA?

The absolute maximum collector current for KSC2786YTA is I_C = 20 mA at T_A = 25°C. Derating applies above 25°C per the thermal resistance curve; continuous operation above 15 mA is recommended only with adequate PCB copper area or forced airflow. This rating aligns with its use in Class-A RF amplifiers and low-power oscillator cores, not switching or power applications.

Is KSC2786YTA pin-compatible with standard TO-92 transistors?

KSC2786YTA uses the TO-92S package - a variant of TO-92 with shorter leads and tighter pitch (1.27 mm vs. standard 1.27–1.30 mm), but identical 1–2–3 pinout order (Emitter–Collector–Base). While mechanically compatible with most TO-92 footprints, its RF-optimized internal construction and Y-class binning make it functionally distinct from generic TO-92 transistors like PN2222 or BC547.

What is the noise figure specification for KSC2786YTA?

The KSC2786YTA has a noise figure of 3.0–5.0 dB measured at V_CE = 6 V, I_C = 1 mA, R_S = 50 Ω, and f = 100 MHz. This low NF enables high-fidelity signal amplification in weak-signal tuner front-ends, directly supporting analog TV and FM broadcast reception standards. The value is confirmed in the "Electrical Characteristics" table of the official KSC2786YTA datasheet.