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

onsemi KSB1151YSTU

Name: KSB1151YSTU
Brand: onsemi
SKU: KSB1151YSTU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KSB1151YSTU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: KSB1151YSTU.pdf

Description:: TRANS PNP 60V 5A TO-126-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

KSB1151YSTU from onsemi is a PNP epitaxial silicon power transistor in TO-126 package, rated for −60 V V_CEO, −5 A DC collector current, and 20 W collector dissipation at T_C = 25°C; it delivers low −0.14 V typical V_CE(sat) at −2 A/−0.2 A drive and supports high-current linear and switching applications such as DC motor control and power supply regulation.

For engineers reviewing the KSB1151YSTU datasheet, pinout, applications, or equivalent options, key selection criteria include verified V_CE(sat) performance at high I_C, h_FE classification (Y-grade: 160–320 at −2 A), TO-126 thermal capability, and complementary pairing with KSD1691 NPN devices in push-pull output stages.

Technical Context

This device operates as a medium-power PNP bipolar junction transistor optimized for linear amplification and saturated switching. Its design emphasizes low saturation voltage under high-current conditions (IC = −2 A, IB = −0.2 A) and robust safe operating area (SOA) up to −60 V and −5 A, validated by forward/reverse bias SOA curves and derating data.

The KSB1151YSTU exhibits graded h_FE performance across operating points: min 100 at −2 A (h_FE2), max 400 at −5 A (h_FE3), and stable cutoff leakage (<−10 µA ICBO at V_CB = −50 V), supporting predictable gain behavior in emitter-follower and series-pass configurations.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−60 V: Maximum sustainable collector-emitter voltage before breakdown in common-emitter configuration.
I_C (DC)	−5 A: Continuous collector current rating defining steady-state power stage capacity.
P_C (T_C=25°C)	20 W: Thermal power limit at case temperature 25°C, enabling high-efficiency heat sinking in TO-126.
V_CE(sat)	−0.14 V (typ): Low saturation voltage at −2 A/−0.2 A, minimizing conduction loss in switching regulators.
h_FE2	160–320: Guaranteed DC current gain range at V_CE = −1 V, I_C = −2 A, ensuring consistent base drive sizing.
t_ON	0.15–1 µs: Fast turn-on time under specified R_L = 5 Ω, V_CC = −10 V conditions, suitable for kHz-range switching.

Pinout & Package

Package: TO-126 (standard outline per MKT-TO126AArev2), thermally enhanced plastic case with metal tab for heatsink mounting; 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 node; electrically connected to metal tab-must be isolated from heatsink unless circuit ground reference.
2	Collector	Main current path into transistor; tied internally to metal tab-requires insulated mounting or system-common connection.
3	Base	Control input; requires negative bias relative to emitter to forward-bias PNP junction and enable conduction.

Key Features

Feature	Design Value
Low V_CE(sat)	−0.14 V typical at −2 A/−0.2 A enables <0.3 W conduction loss in 12 V motor drivers.
High I_C capability	−5 A DC rating supports direct drive of solenoids, relays, and medium-power DC loads without external buffering.
Thermal robustness	20 W dissipation at T_C = 25°C and 150°C max junction temperature allow operation in industrial ambient up to 85°C with proper heatsinking.
Complementary pairing	Designed as PNP counterpart to KSD1691 NPN, enabling matched push-pull output stages with symmetric gain and SOA.

Applications

DC Motor Control	Linear Voltage Regulator
Use Scenario: H-bridge low-side driver for 24 V brushed DC motors in industrial actuators. IC Role / Device Role / Timing Role: PNP switch controlling motor current direction and braking via emitter-follower configuration. Use Value: −0.14 V V_CE(sat) reduces power loss by >40% vs. generic PNP transistors at −2 A, improving thermal margin.	Use Scenario: Series pass element in adjustable 3–15 V, 3 A linear regulator for test equipment power rails. IC Role / Device Role / Timing Role: High-current series pass transistor regulating output voltage under variable load. Use Value: 20 W collector dissipation at T_C = 25°C supports full-load operation with 10°C/W heatsink without thermal shutdown.
Switching Power Supply	Audio Output Stage
Use Scenario: Saturated switch in 50 kHz flyback converter primary side for 48 V telecom power supplies. IC Role / Device Role / Timing Role: High-speed PNP switch turning on/off transformer primary current with minimal storage time (t_STG ≤ 2.5 µs). Use Value: 0.78 µs typical storage time ensures clean turn-off transition, reducing cross-conduction losses in quasi-resonant topologies.	Use Scenario: Complementary emitter-follower output stage in Class AB audio amplifier delivering 10 W into 8 Ω. IC Role / Device Role / Timing Role: PNP half of push-pull pair driving speaker load with matched h_FE and SOA to KSD1691. Use Value: h_FE2 = 160–320 at −2 A ensures symmetrical drive capability and low crossover distortion in audio band.

DC Motor Control

Linear Voltage Regulator

Use Scenario: H-bridge low-side driver for 24 V brushed DC motors in industrial actuators.

IC Role / Device Role / Timing Role: PNP switch controlling motor current direction and braking via emitter-follower configuration.

Use Value: −0.14 V V_CE(sat) reduces power loss by >40% vs. generic PNP transistors at −2 A, improving thermal margin.

Use Scenario: Series pass element in adjustable 3–15 V, 3 A linear regulator for test equipment power rails.

IC Role / Device Role / Timing Role: High-current series pass transistor regulating output voltage under variable load.

Use Value: 20 W collector dissipation at T_C = 25°C supports full-load operation with 10°C/W heatsink without thermal shutdown.

Switching Power Supply

Audio Output Stage

Use Scenario: Saturated switch in 50 kHz flyback converter primary side for 48 V telecom power supplies.

IC Role / Device Role / Timing Role: High-speed PNP switch turning on/off transformer primary current with minimal storage time (t_STG ≤ 2.5 µs).

Use Value: 0.78 µs typical storage time ensures clean turn-off transition, reducing cross-conduction losses in quasi-resonant topologies.

Use Scenario: Complementary emitter-follower output stage in Class AB audio amplifier delivering 10 W into 8 Ω.

IC Role / Device Role / Timing Role: PNP half of push-pull pair driving speaker load with matched h_FE and SOA to KSD1691.

Use Value: h_FE2 = 160–320 at −2 A ensures symmetrical drive capability and low crossover distortion in audio band.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD127G	TO-252 (DPAK), −100 V V_CEO, −8 A I_C, higher V_CE(sat) (−0.5 V typ at −3 A)	Better voltage headroom but lower thermal efficiency in low-voltage, high-current apps	Prefer for designs requiring >−60 V blocking or surface-mount assembly; not pin-compatible.
BD139	TO-126, −80 V V_CEO, −1.5 A I_C, lower power dissipation (12.5 W)	Lower current handling limits use in >2 A continuous loads	Acceptable for cost-sensitive, lower-power replacements where I_C ≤ 1.5 A and V_CEO ≥ −80 V suffices.

Compared with MJD127G and BD139, the KSB1151YSTU offers optimal balance of −60 V rating, −5 A current, and −0.14 V V_CE(sat) in through-hole TO-126-making it uniquely suited for legacy industrial power stages where thermal density and saturation loss are critical.

Availability

KSB1151YSTU is available at Aetrix Electronics and suitable for DC motor control, linear voltage regulation, switching power supply, and audio output stage applications requiring stable component supply despite end-of-life status.

Supply support for KSB1151YSTU 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 power management, analog, and sensing technologies for automotive, industrial, and cloud infrastructure markets.

The KSB1151YSTU belongs to onsemi's legacy discrete power transistor family, engineered specifically for high-reliability linear and switching power applications demanding robust SOA, low saturation loss, and thermal stability in industrial environments.

FAQ

What is the pin configuration of the KSB1151YSTU?

The KSB1151YSTU uses a TO-126 package with three terminals: Pin 1 is Emitter, Pin 2 is Collector (internally connected to the metal tab), and Pin 3 is Base. This configuration is standardized per MKT-TO126AArev2 and confirmed in the official onsemi datasheet Rev. 3 (July 2025). Proper heatsink isolation is required when Pin 1 or Pin 2 connects to system ground.

Is the KSB1151YSTU still in active production?

No-the KSB1151YSTU is discontinued and not recommended for new designs per the official onsemi datasheet. However, Aetrix Electronics maintains limited legacy inventory with full traceability and supports ongoing production programs requiring this specific variant for BOM continuity and repair scenarios.

What does the 'YSTU' suffix indicate in KSB1151YSTU?

The 'YSTU' suffix identifies the KSB1151YSTU as the Y-grade h_FE variant (h_FE2 = 160–320 at −2 A) in TSSTU terminal length configuration (D = 3.45–4.05 mm, E = 6.45–7.45 mm), per onsemi's packaging specification table in the KSB1151 datasheet Rev. 3.

Can the KSB1151YSTU replace the KSB1151TU?

Yes-the KSB1151YSTU is functionally identical to KSB1151TU except for h_FE grading and terminal length: YSTU specifies Y-grade gain (160–320) and TSSTU lead dimensions, while TU denotes standard-length leads and unspecified h_FE bin. Electrical specs, package outline, and pinout remain fully compatible.

What is the maximum safe operating area (SOA) for the KSB1151YSTU?

The KSB1151YSTU SOA is defined by five limiting curves in the datasheet: DC, pulsed (2 ms, 10 ms, 200 ms), and second breakdown. At T_C = 25°C, it supports −60 V × −5 A (DC), −40 V × −8 A (pulsed), and remains within safe limits up to 150°C junction temperature-verified in Figures 4–6 of the KSB1151 Rev. 3 datasheet.

KSB1151YSTU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Tube

Product Status:: Last Time Buy

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 5 A

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 200mA, 2A

Current - Collector Cutoff (Max):: 10µA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 160 @ 2A, 1V

Power - Max:: 1.3 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126-3

KSB1151YSTU FAQ

1.How can I place an order for KSB1151YSTU through Aetrix?

Please submit a Request for Quotation (RFQ) for KSB1151YSTU 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 KSB1151YSTU reliable?

The price and inventory of KSB1151YSTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSB1151YSTU is usually 5 days.

3.What payment methods are accepted for KSB1151YSTU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSB1151YSTU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSB1151YSTU?

KSB1151YSTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSB1151YSTU 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 KSB1151YSTU?

For technical support, including KSB1151YSTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSB1151YSTU requirements.

6.How does Aetrix verify that KSB1151YSTU is sourced from the original manufacturer or authorized distributors?

All KSB1151YSTU 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 KSB1151YSTU meets industry standards.

7.What is the process for return or replacement of KSB1151YSTU?

All KSB1151YSTU units undergo pre-shipment inspection (PSI). If there is an issue with KSB1151YSTU, 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 KSB1151YSTU part is unused and in its original packaging.

Return procedure for KSB1151YSTU:

1.Submit a request within 90 days.

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

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