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

onsemi KSA1142YSTU

Name: KSA1142YSTU
Brand: onsemi
SKU: KSA1142YSTU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KSA1142YSTU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-225AA, TO-126-3

Datasheet:: KSA1142YSTU.pdf

Description:: TRANS PNP 180V 0.1A TO-126-3

Quantity:: RFQ Add To RFQ list

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Inventory:5,199

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Product details

Overview

KSA1142YSTU from onsemi is a PNP epitaxial silicon transistor rated for -180 V V_CEO, -100 mA I_C, and 8 W P_C (T_C=25°C), optimized for audio and high-frequency power amplifier stages in discrete linear circuits.

For engineers reviewing the KSA1142YSTU datasheet, pinout, applications, or equivalent options, key selection factors include its TO-126 package, h_FE range of 160–320 at -10 mA, f_T = 180 MHz, low V_CE(sat) (-0.16 V typ.), and complementary pairing with KSC2682.

Technical Context

The KSA1142YSTU operates as a medium-power PNP bipolar junction transistor with DC current gain classified in the Y group (h_FE2 = 160–320 at V_CE = -5 V, I_C = -10 mA). It supports linear amplification up to 180 MHz and exhibits low saturation voltages under defined drive conditions.

Its safe operating area (SOA) is defined for pulsed and DC operation, with thermal derating beginning above 25°C case temperature. The device uses epitaxial base construction and is specified for junction temperatures up to 150°C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-180 V - Maximum collector-emitter blocking voltage before breakdown in common-emitter configuration
I_C	-100 mA - Continuous collector current rating defining linear output capability
P_C (T_C=25°C)	8 W - Maximum power dissipation at heatsink-mounted case temperature, enabling medium-power stage use
h_FE2	160–320 - Verified DC current gain range at -10 mA collector current, critical for bias stability in amplifier designs
f_T	180 MHz - Unity-gain frequency confirming suitability for HF power amplification up to ~30 MHz fundamental
V_CE(sat)	-0.16 V (typ.) - Low saturation voltage at I_C = -50 mA / I_B = -5 mA, reducing conduction loss in switching or Class AB output stages
C_ob	4.5–7 pF - Output capacitance at -10 V V_CB, influencing high-frequency gain roll-off and stability compensation

Pinout & Package

Package: TO-126 (standard outline per drawing MKT-TO126AArev2), thermally enhanced through-hole package with metal tab for heatsinking. Terminal length "D" = 3.45–4.05 mm; "E" = 6.45–7.45 mm (TSSTU variant).

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Current exit terminal; connected to most negative rail in PNP amplifier configurations
2	Collector	Main current sink; electrically tied to heatsink tab and requires isolation if mounted to grounded chassis
3	Base	Control input; requires current-limited drive to achieve specified h_FE and avoid thermal runaway

Key Features

Feature	Design Value
Complementary Pairing	Designed as direct PNP complement to NPN KSC2682 - matched V_CEO, I_C, f_T, and package for push-pull amplifier symmetry
High f_T	180 MHz gain-bandwidth enables stable operation in RF driver and wideband audio output stages up to 30 MHz
Low V_CE(sat)	-0.16 V typical at I_C/I_B = 10 ensures <1% voltage drop across transistor in saturated switching or Class AB bias
Thermal Robustness	150°C max junction temperature and SOA-defined derating allow reliable operation with moderate heatsinking in industrial amplifiers
Low Noise Figure	4 dB NF at 1 MHz (R_S = 10 kΩ) supports low-noise pre-driver and line-level amplification roles

Applications

Audio Frequency Power Amplifier	High Frequency Power Amplifier
Use Scenario: Final output stage in discrete Class AB hi-fi amplifiers delivering 5–20 W into 4–8 Ω loads. IC Role / Device Role / Timing Role: PNP power switch in complementary emitter-follower or common-emitter topology. Use Value: Matches KSC2682's V_CEO and f_T to maintain symmetrical slew rate and crossover distortion control.	Use Scenario: Driver stage in VHF RF power amplifiers (30–100 MHz) for broadcast or test equipment. IC Role / Device Role / Timing Role: Medium-power gain block with broadband linear response up to 30 MHz fundamental. Use Value: 180 MHz f_T and 7 pF C_ob support stable gain with minimal neutralization in tuned amplifier designs.
Discrete Linear Regulator Pass Element	Industrial Signal Conditioning Stage
Use Scenario: Series pass transistor in adjustable linear regulators requiring >100 mA load current and 150 V headroom. IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output via base-emitter voltage feedback. Use Value: -180 V V_CEO and 8 W P_C enable operation with high input-output differential without derating.	Use Scenario: Precision current source or active load in analog sensor signal conditioning circuits. IC Role / Device Role / Timing Role: Constant-current sink with stable h_FE and low thermal drift over -40°C to +125°C ambient. Use Value: Tight h_FE classification (Y group) and 4.5 pF C_ob minimize gain variation and capacitive loading in feedback networks.

Audio Frequency Power Amplifier

High Frequency Power Amplifier

Use Scenario: Final output stage in discrete Class AB hi-fi amplifiers delivering 5–20 W into 4–8 Ω loads.

IC Role / Device Role / Timing Role: PNP power switch in complementary emitter-follower or common-emitter topology.

Use Value: Matches KSC2682's V_CEO and f_T to maintain symmetrical slew rate and crossover distortion control.

Use Scenario: Driver stage in VHF RF power amplifiers (30–100 MHz) for broadcast or test equipment.

IC Role / Device Role / Timing Role: Medium-power gain block with broadband linear response up to 30 MHz fundamental.

Use Value: 180 MHz f_T and 7 pF C_ob support stable gain with minimal neutralization in tuned amplifier designs.

Discrete Linear Regulator Pass Element

Industrial Signal Conditioning Stage

Use Scenario: Series pass transistor in adjustable linear regulators requiring >100 mA load current and 150 V headroom.

IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output via base-emitter voltage feedback.

Use Value: -180 V V_CEO and 8 W P_C enable operation with high input-output differential without derating.

Use Scenario: Precision current source or active load in analog sensor signal conditioning circuits.

IC Role / Device Role / Timing Role: Constant-current sink with stable h_FE and low thermal drift over -40°C to +125°C ambient.

Use Value: Tight h_FE classification (Y group) and 4.5 pF C_ob minimize gain variation and capacitive loading in feedback networks.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD112G	TO-220 package; higher P_C (1.5 W @ T_A); h_FE = 1000–3000 at I_C = -1 A; lower f_T (~3 MHz)	Better suited for high-current, low-frequency switching; not suitable for HF amplification due to limited bandwidth	Select when needing higher continuous current and TO-220 mounting compatibility, not for RF/audio linearity
KSA992FBU	Same TO-126 package; V_CEO = -160 V; h_FE = 200–400; f_T = 120 MHz; P_C = 1 W @ T_A	Lower voltage rating and reduced power handling limit use in high-headroom or high-dissipation designs	Acceptable for cost-sensitive audio preamp stages where -160 V and 1 W suffice; verify SOA compliance

Compared with MJD112G and KSA992FBU, the KSA1142YSTU offers superior high-frequency linearity (180 MHz f_T) and higher voltage capability (-180 V), making it uniquely appropriate for symmetric push-pull audio and VHF driver applications where both bandwidth and breakdown margin are critical.

Availability

KSA1142YSTU is available at Aetrix Electronics and suitable for audio frequency power amplifiers, high frequency power amplifiers, and discrete linear regulator designs requiring stable component supply despite end-of-life status.

Supply support for KSA1142YSTU 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

onsemi (formerly Fairchild Semiconductor) is a global semiconductor supplier focused on energy-efficient technologies for automotive, industrial, cloud, and IoT applications.

The KSA1142YSTU belongs to onsemi's legacy discrete bipolar transistor product line, engineered specifically for high-voltage, medium-power linear amplification and complementary symmetry in analog power circuits.

FAQ

What is the package type and pin configuration of KSA1142YSTU?

The KSA1142YSTU uses a TO-126 package with three leads: Pin 1 is Emitter, Pin 2 is Collector (connected to the metal tab), and Pin 3 is Base. This configuration is standardized per drawing MKT-TO126AArev2, with TSSTU terminal lengths (D = 3.45–4.05 mm, E = 6.45–7.45 mm). Thermal design must account for tab isolation when mounting to grounded heatsinks.

Is KSA1142YSTU still recommended for new designs?

No - KSA1142YSTU is officially discontinued and not recommended for new designs per onsemi documentation (Rev. 1, May 2024). However, Aetrix Electronics maintains legacy inventory and provides lifecycle coordination support. Engineers should consult onsemi for approved replacements such as the KSA992 series or evaluate functional alternatives like MJD112G where package and performance permit.

What does the 'YSTU' suffix indicate in KSA1142YSTU?

The 'YSTU' suffix identifies the KSA1142YSTU as the TSSTU variant of the KSA1142 family, specifying terminal length dimensions (D = 3.45–4.05 mm, E = 6.45–7.45 mm) and packaging format per onsemi's TO-126 mechanical drawing MKT-TO126AArev2. It does not denote parameter grading or reliability enhancement - electrical specs match the base KSA1142.

How does KSA1142YSTU compare to its complementary NPN counterpart KSC2682?

KSA1142YSTU and KSC2682 are engineered as matched complementary pairs: both share identical V_CEO (-180 V), I_C (-100 mA / +100 mA), f_T (180 MHz), and TO-126 packaging. Their h_FE ranges overlap (KSA1142YSTU Y-group: 160–320; KSC2682 Y-group: 160–320), enabling balanced push-pull operation with minimized crossover distortion in audio amplifier output stages.

What are the safe operating area (SOA) limitations for KSA1142YSTU?

KSA1142YSTU's SOA is defined for both DC and pulsed operation, with boundaries set by secondary breakdown, thermal limits, and maximum current. At T_C = 25°C, it supports up to -100 mA at -180 V in pulse mode (PW ≤ 350 µs, duty ≤ 2%), but DC operation is limited to -100 mA only below ~20 V V_CE. Derating begins linearly above 25°C case temperature, reaching zero power at 150°C junction temperature.

KSA1142YSTU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-225AA, TO-126-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 100 mA

Voltage - Collector Emitter Breakdown (Max):: 180 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: 1µA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 160 @ 10mA, 5V

Power - Max:: 1.2 W

Frequency - Transition:: 180MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126-3

KSA1142YSTU FAQ

1.How can I place an order for KSA1142YSTU through Aetrix?

Please submit a Request for Quotation (RFQ) for KSA1142YSTU 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 KSA1142YSTU reliable?

The price and inventory of KSA1142YSTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSA1142YSTU is usually 5 days.

3.What payment methods are accepted for KSA1142YSTU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSA1142YSTU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSA1142YSTU?

KSA1142YSTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSA1142YSTU 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 KSA1142YSTU?

For technical support, including KSA1142YSTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSA1142YSTU requirements.

6.How does Aetrix verify that KSA1142YSTU is sourced from the original manufacturer or authorized distributors?

All KSA1142YSTU 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 KSA1142YSTU meets industry standards.

7.What is the process for return or replacement of KSA1142YSTU?

All KSA1142YSTU units undergo pre-shipment inspection (PSI). If there is an issue with KSA1142YSTU, 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 KSA1142YSTU part is unused and in its original packaging.

Return procedure for KSA1142YSTU:

1.Submit a request within 90 days.

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

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