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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Bipolar RF Transistors

onsemi KSC1730OTA

Name: KSC1730OTA
Brand: onsemi
SKU: KSC1730OTA
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KSC1730OTA

Manufacturer:: onsemi

Category:: Bipolar RF Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: KSC1730OTA.pdf

Description:: RF TRANS NPN 15V 1.1GHZ TO92-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

KSC1730OTA from Fairchild Semiconductor is an NPN epitaxial silicon transistor designed for VHF/UHF tuner oscillator circuits, featuring f_T = 1100 MHz (max), C_ob = 1.5 pF (max), V_CEO = 15 V, I_C = 50 mA, and P_C = 250 mW in TO-92 package.

For engineers reviewing the KSC1730OTA datasheet, pinout, applications, or equivalent options, key selection criteria include high-frequency gain-bandwidth performance, low output capacitance, saturation voltage under defined drive conditions, DC current gain classification (R/O/Y), and TO-92 thermal and mounting compatibility.

Technical Context

This transistor employs epitaxial base construction to achieve high f_T up to 1100 MHz at I_C = 5 mA and V_CE = 10 V, with guaranteed C_ob ≤ 1.5 pF at V_CB = 10 V and f = 1 MHz - critical for stable VHF/UHF oscillator tuning and minimal parasitic loading.

It operates with V_CE(sat) = 0.5 V max at I_C = 10 mA / I_B = 1 mA, supports h_FE ranging 40–240 (classified R/O/Y), and maintains safe junction temperature up to 150°C with 250 mW power dissipation in ambient-constrained TO-92 mounting.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	15 V - maximum collector-emitter voltage before breakdown; defines safe operating range in tuned amplifier stages.
f_T	1100 MHz (max) - current gain bandwidth product; enables stable oscillation and amplification up to UHF band.
C_ob	1.5 pF (max) - collector-base output capacitance; minimizes frequency pulling and phase noise in oscillator tanks.
h_FE	40–240 - DC current gain range across R/O/Y classifications; allows gain binning for consistent circuit biasing.
V_CE(sat)	0.5 V (max) at I_C=10 mA/I_B=1 mA - low saturation voltage ensures efficient switching and reduced power loss in active loads.
P_C	250 mW - maximum collector power dissipation in TO-92; sets thermal limits for continuous RF operation.

Pinout & Package

Package: TO-92 - standard through-hole plastic package with 3.60 mm lead spacing, 4.58 mm body height, and 1.27 mm lead diameter; optimized for manual assembly and RF board layout with low thermal resistance.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Reference node for bias network; connected to ground or emitter degeneration resistor in common-base/common-emitter oscillators.
2 (Collector)	Active output terminal	Drives tank circuit or next stage; requires impedance-matched trace routing to preserve f_T and minimize C_ob coupling.
3 (Base)	Control input terminal	Receives bias current or RF feedback signal; high-impedance node sensitive to stray capacitance and layout parasitics.

Key Features

Feature	Design Value
High f_T	1100 MHz max enables reliable operation in 30–1000 MHz VHF/UHF oscillator designs without external neutralization.
Low C_ob	≤1.5 pF reduces unwanted coupling between collector and base, improving oscillator stability and Q-factor of resonant circuits.
TO-92 RF-optimized layout	Standardized lead pitch and body dimensions support repeatable PCB footprint and thermal management in tuner modules.
h_FE classification	R/O/Y bins (40–80 / 70–140 / 120–240) allow precise gain matching for production consistency in multi-unit tuner assemblies.

Applications

TV Tuner Oscillator	VHF Band Amplifier
Use Scenario: Local oscillator in analog TV tuner front-end generating 45–230 MHz signals for mixer downconversion. IC Role / Device Role / Timing Role: NPN transistor configured as Colpitts or Clapp oscillator core, providing gain and phase shift at target frequency. Use Value: f_T = 1100 MHz and C_ob = 1.5 pF ensure stable oscillation with low phase noise and minimal frequency drift over temperature.	Use Scenario: Low-noise preamplifier stage in VHF receiver front-end before mixer or IF filter. IC Role / Device Role / Timing Role: Common-emitter RF amplifier biased for linear small-signal gain in 30–300 MHz band. Use Value: High h_FE and low V_CE(sat) enable >15 dB gain with <0.5 dB noise figure when matched to 50 Ω source/load.
UHF Tuner Oscillator	RF Signal Generator Stage
Use Scenario: Oscillator in UHF tuner (470–862 MHz) for digital terrestrial TV reception. IC Role / Device Role / Timing Role: Active device in Hartley or tuned-collector oscillator topology driving ceramic or SAW resonator load. Use Value: Guaranteed f_T ≥ 800 MHz (typ) and tight C_ob tolerance ensure start-up reliability and frequency accuracy across production lots.	Use Scenario: Fixed-frequency RF source in test equipment or remote control transmitter modules. IC Role / Device Role / Timing Role: Class-A or Class-C amplifier delivering clean harmonic-free output at fixed carrier frequency. Use Value: Low V_CE(sat) and controlled h_FE binning reduce amplitude variation and improve output power repeatability across units.

TV Tuner Oscillator

VHF Band Amplifier

Use Scenario: Local oscillator in analog TV tuner front-end generating 45–230 MHz signals for mixer downconversion.

IC Role / Device Role / Timing Role: NPN transistor configured as Colpitts or Clapp oscillator core, providing gain and phase shift at target frequency.

Use Value: f_T = 1100 MHz and C_ob = 1.5 pF ensure stable oscillation with low phase noise and minimal frequency drift over temperature.

Use Scenario: Low-noise preamplifier stage in VHF receiver front-end before mixer or IF filter.

IC Role / Device Role / Timing Role: Common-emitter RF amplifier biased for linear small-signal gain in 30–300 MHz band.

Use Value: High h_FE and low V_CE(sat) enable >15 dB gain with <0.5 dB noise figure when matched to 50 Ω source/load.

UHF Tuner Oscillator

RF Signal Generator Stage

Use Scenario: Oscillator in UHF tuner (470–862 MHz) for digital terrestrial TV reception.

IC Role / Device Role / Timing Role: Active device in Hartley or tuned-collector oscillator topology driving ceramic or SAW resonator load.

Use Value: Guaranteed f_T ≥ 800 MHz (typ) and tight C_ob tolerance ensure start-up reliability and frequency accuracy across production lots.

Use Scenario: Fixed-frequency RF source in test equipment or remote control transmitter modules.

IC Role / Device Role / Timing Role: Class-A or Class-C amplifier delivering clean harmonic-free output at fixed carrier frequency.

Use Value: Low V_CE(sat) and controlled h_FE binning reduce amplitude variation and improve output power repeatability across units.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SC3356	f_T = 6.5 GHz (min), C_ob = 0.7 pF - higher frequency capability but tighter bias sensitivity.	Used in higher-UHF/SHF LNA and oscillator designs beyond 1 GHz; requires precision bias network.	Select when extending operation above 900 MHz or requiring lower capacitance; verify thermal derating in TO-92.
MPSH10	f_T = 650 MHz (min), h_FE = 60–120 - lower bandwidth and narrower gain range than KSC1730OTA.	Suitable for VHF-only tuners and general-purpose RF switching where 1100 MHz headroom is unnecessary.	Choose for cost-sensitive VHF applications with relaxed f_T and C_ob requirements; no re-layout needed due to identical TO-92 pinout.

Compared with 2SC3356 and MPSH10, the KSC1730OTA delivers optimal balance of UHF-ready f_T, low C_ob, and production-friendly h_FE binning - making it preferred for legacy and cost-optimized TV tuner oscillator designs where 1100 MHz margin and 1.5 pF capacitance are design-critical.

Availability

KSC1730OTA is available at Aetrix Electronics and suitable for TV tuner oscillator circuits, VHF/UHF RF amplifiers, analog broadcast receiver front-ends, and consumer electronics RF signal generation requiring stable component supply and long-term obsolescence mitigation.

Supply support for KSC1730OTA 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 KSC1730OTA belongs to Fairchild's legacy RF transistor product line, engineered specifically for high-frequency oscillator and amplifier functions in analog television and broadcast receiver systems.

FAQ

What is the maximum operating frequency supported by the KSC1730OTA?

The KSC1730OTA has a current gain bandwidth product (f_T) of up to 1100 MHz, verified under V_CE = 10 V and I_C = 5 mA. This makes the KSC1730OTA suitable for stable oscillation and amplification in VHF and lower-UHF bands (up to ~800 MHz practical design limit), not for microwave frequencies requiring >2 GHz f_T.

Does the KSC1730OTA have a specified h_FE range, and how is it binned?

Yes - the KSC1730OTA is classified into three h_FE bins: R (40–80), O (70–140), and Y (120–240), measured at V_CE = 10 V and I_C = 5 mA. The KSC1730OTA part number itself does not indicate bin; actual h_FE is marked on tape-and-reel packaging or individual units per Fairchild's labeling convention.

What is the pin configuration of the KSC1730OTA in TO-92 package?

The KSC1730OTA uses standard TO-92 pinout: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base - confirmed in Fairchild's Rev. B1 datasheet, Figure "Package Dimensions". This matches JEDEC TO-92 outline and is electrically identical to other Fairchild RF transistors like KSC1845.

Can the KSC1730OTA replace the 2N5179 in VHF oscillator designs?

The KSC1730OTA offers higher f_T (1100 MHz vs. 2N5179's 600 MHz) and lower C_ob (1.5 pF vs. ~3 pF), making it a functional upgrade in VHF oscillator applications. However, the KSC1730OTA is not pin-compatible with 2N5179 (which uses E-B-C order), so PCB layout revision is required despite same TO-92 footprint.

Is the KSC1730OTA suitable for use in automotive or industrial temperature environments?

The KSC1730OTA specifies T_J = –55°C to +150°C and T_STG = –55°C to +150°C, but its electrical characteristics are only guaranteed from –25°C to +85°C per datasheet conditions. For extended-temperature automotive or industrial use, derating of P_C and verification of h_FE/f_T stability across full range is required - the KSC1730OTA itself is not AEC-Q101 qualified.

KSC1730OTA Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Transistor Type:: NPN

Voltage - Collector Emitter Breakdown (Max):: 15V

Frequency - Transition:: 1.1GHz

Noise Figure (dB Typ @ f):: -

Gain:: -

Power - Max:: 250mW

DC Current Gain (hFE) (Min) @ Ic, Vce:: 70 @ 5mA, 10V

Current - Collector (Ic) (Max):: 50mA

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

KSC1730OTA FAQ

1.How can I place an order for KSC1730OTA through Aetrix?

Please submit a Request for Quotation (RFQ) for KSC1730OTA 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 KSC1730OTA reliable?

The price and inventory of KSC1730OTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC1730OTA is usually 5 days.

3.What payment methods are accepted for KSC1730OTA?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC1730OTA transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSC1730OTA?

KSC1730OTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSC1730OTA 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 KSC1730OTA?

For technical support, including KSC1730OTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC1730OTA requirements.

6.How does Aetrix verify that KSC1730OTA is sourced from the original manufacturer or authorized distributors?

All KSC1730OTA 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 KSC1730OTA meets industry standards.

7.What is the process for return or replacement of KSC1730OTA?

All KSC1730OTA units undergo pre-shipment inspection (PSI). If there is an issue with KSC1730OTA, 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 KSC1730OTA part is unused and in its original packaging.

Return procedure for KSC1730OTA:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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