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

onsemi KSB1151YSTSTU

Name: KSB1151YSTSTU
Brand: onsemi
SKU: KSB1151YSTSTU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KSB1151YSTSTU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: KSB1151YSTSTU.pdf

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

Quantity:: RFQ Add To RFQ list

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Product details

Overview

KSB1151YSTSTU from onsemi (formerly Fairchild Semiconductor) 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 V_CE(sat) of −0.14 V (typ.) at I_C = −2 A / I_B = −0.2 A, and is used in linear power regulation and high-current switching circuits.

For engineers reviewing the KSB1151YSTSTU datasheet, pinout, applications, or equivalent options, key selection criteria include verified PNP polarity, TO-126 mechanical footprint with emitter-collector-base terminal order, −60 V breakdown rating, h_FE classification (Y: 160–320 at I_C = −2 A), and discontinuation status requiring legacy design support planning.

Technical Context

This device operates as a medium-power PNP bipolar junction transistor with complementary pairing to the NPN KSD1691. Its safe operating area (SOA) is defined by both dissipation-limited and second-breakdown boundaries, with pulse capability up to −8 A (10 ms, 50% duty cycle).

DC current gain is specified across three test conditions: h_FE1 = 60–200 at I_C = −0.1 A, h_FE2 = 160–320 (Y-class), and h_FE3 = 50–400 at I_C = −5 A, supporting both linear amplification and saturated switching roles under varying load currents.

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 handling capacity at ambient temperature, defining steady-state load drive capability.
P_C (T_C=25°C)	20 W: Thermal power limit when case temperature is maintained at 25°C, requiring heatsinking for full-rating operation.
V_CE(sat)	−0.14 V (typ.): Low saturation voltage at I_C = −2 A / I_B = −0.2 A, minimizing conduction loss in switching applications.
h_FE2	160–320 (Y-class): Verified DC current gain range at V_CE = −1 V, I_C = −2 A, enabling predictable base drive sizing.
t_ON	0.15–1 µs: Fast turn-on time under specified resistive-load switching conditions, supporting kHz-range switching.

Pinout & Package

Package: TO-126 (standard outline per MKT-TO126AArev2), thermally enhanced plastic power package with metal tab connected to collector; terminals arranged left-to-right (viewed from front): Emitter (1), Collector (2), Base (3).

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current source terminal for PNP operation	Connected to higher potential rail in typical switch configurations; requires robust trace routing for −5 A paths.
2 (Collector)	Main current sink terminal	Internally bonded to metal tab - electrically and thermally tied to heatsink mounting surface.
3 (Base)	Control input for minority-carrier injection	Requires current-limited drive (max I_B = −1 A) to avoid secondary breakdown during saturation.

Key Features

Feature	Design Value
Low V_CE(sat)	−0.14 V typ. at I_C = −2 A reduces conduction losses by >30% vs. standard PNP transistors with >−0.2 V saturation.
High I_C rating	−5 A DC current supports direct driving of solenoids, relays, and motor windings without external current boosting.
20 W thermal capability	Enables operation at full current with moderate heatsinking (e.g., 2.5°C/W sink) at T_C ≤ 75°C.
Complementary pairing	Designed as PNP match to KSD1691 NPN, facilitating push-pull output stages and H-bridge driver designs.

Applications

Linear Power Regulator	DC Motor Driver Stage
Use Scenario: Used as pass transistor in adjustable negative-voltage regulators (e.g., −5 V to −15 V outputs) delivering up to 3 A continuous load current. IC Role / Device Role / Timing Role: PNP series pass element controlling output voltage via feedback-controlled base current. Use Value: Low V_CE(sat) minimizes dropout voltage and thermal stress under full load, extending regulator efficiency and reliability.	Use Scenario: Implements high-side switch in brushed DC motor control circuits for industrial actuators requiring bidirectional torque. IC Role / Device Role / Timing Role: PNP high-side driver enabling ground-referenced logic control of negative-rail motor supply. Use Value: −60 V V_CEO withstands inductive kickback from 48 V motors; TO-126 tab enables direct heatsink attachment for thermal stability.
Relay/Solenoid Driver	Discrete Audio Output Stage
Use Scenario: Drives 24 V/2 A electromagnetic relays in PLC I/O modules where fast turn-off is required to suppress contact arcing. IC Role / Device Role / Timing Role: Saturated PNP switch turning relay coil on/off with controlled base drive and snubber integration. Use Value: t_STG = 0.78–2.5 µs and t_F = 0.18–1 µs enable clean de-energization, reducing relay wear and EMI.	Use Scenario: Forms emitter-follower output stage in discrete Class-AB audio amplifiers delivering ±10 V into 8 Ω loads. IC Role / Device Role / Timing Role: Linear-mode PNP output transistor providing low-output-impedance current sourcing capability. Use Value: h_FE2 = 160–320 ensures stable biasing across unit-to-unit variation; SOA curve supports safe operation under reactive speaker loads.

Linear Power Regulator

DC Motor Driver Stage

Use Scenario: Used as pass transistor in adjustable negative-voltage regulators (e.g., −5 V to −15 V outputs) delivering up to 3 A continuous load current.

IC Role / Device Role / Timing Role: PNP series pass element controlling output voltage via feedback-controlled base current.

Use Value: Low V_CE(sat) minimizes dropout voltage and thermal stress under full load, extending regulator efficiency and reliability.

Use Scenario: Implements high-side switch in brushed DC motor control circuits for industrial actuators requiring bidirectional torque.

IC Role / Device Role / Timing Role: PNP high-side driver enabling ground-referenced logic control of negative-rail motor supply.

Use Value: −60 V V_CEO withstands inductive kickback from 48 V motors; TO-126 tab enables direct heatsink attachment for thermal stability.

Relay/Solenoid Driver

Discrete Audio Output Stage

Use Scenario: Drives 24 V/2 A electromagnetic relays in PLC I/O modules where fast turn-off is required to suppress contact arcing.

IC Role / Device Role / Timing Role: Saturated PNP switch turning relay coil on/off with controlled base drive and snubber integration.

Use Value: t_STG = 0.78–2.5 µs and t_F = 0.18–1 µs enable clean de-energization, reducing relay wear and EMI.

Use Scenario: Forms emitter-follower output stage in discrete Class-AB audio amplifiers delivering ±10 V into 8 Ω loads.

IC Role / Device Role / Timing Role: Linear-mode PNP output transistor providing low-output-impedance current sourcing capability.

Use Value: h_FE2 = 160–320 ensures stable biasing across unit-to-unit variation; SOA curve supports safe operation under reactive speaker loads.

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-220 package; −100 V V_CEO; h_FE = 30–120 at I_C = −2 A; higher voltage rating but lower gain consistency.	Preferred in higher-voltage industrial controls (>60 V bus); less suitable for precision linear regulation due to wider h_FE spread.	Select MJD127G only if V_CEO margin >40 V is required and TO-220 layout compatibility exists.
BD139	TO-126 package; −80 V V_CEO; −1.5 A I_C (DC); h_FE = 40–250; lower current and power capability.	Suitable for low-power analog stages or signal-level switching; cannot replace KSB1151YSTSTU in ≥3 A load applications.	Use BD139 only for prototyping or low-current legacy upgrades where thermal derating permits.

Compared with MJD127G and BD139, the KSB1151YSTSTU offers superior current-handling (−5 A) and gain consistency (Y-class 160–320) in the TO-126 form factor, making it uniquely suited for medium-power linear and switching roles where package size and thermal interface are constrained.

Availability

KSB1151YSTSTU is available at Aetrix Electronics and suitable for industrial control systems, legacy power supply refurbishment, and repair programs requiring stable component supply despite its discontinued status.

Supply support for KSB1151YSTSTU 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud power applications.

The KSB1151YSTSTU belongs to onsemi's legacy bipolar power transistor product line, designed specifically for robust, cost-effective medium-power linear regulation and switching in industrial and consumer equipment.

FAQ

Is KSB1151YSTSTU still in active production?

No, KSB1151YSTSTU is discontinued and not recommended for new designs per onsemi documentation. However, Aetrix Electronics maintains limited legacy stock and supports repair and maintenance programs with traceable, tested units sourced from authorized channels.

What does the "YSTSTU" suffix indicate for KSB1151YSTSTU?

The "YSTSTU" suffix specifies the TO-126 package variant with terminal length D = 3.45–4.05 mm and E = 6.45–7.45 mm per MKT-TO126AArev2 drawing, and denotes Y-class h_FE (160–320) and tape-and-reel packaging for automated assembly.

Can KSB1151YSTSTU be used as a direct replacement for KSB1151YBU?

KSB1151YSTSTU and KSB1151YBU share identical electrical specifications and TO-126 package, but differ in terminal lengths and packaging format. KSB1151YSTSTU uses TSSTU lead dimensions and tape-and-reel; KSB1151YBU uses different lead specs and bulk packaging. Mechanical fit must be verified per board footprint.

What is the maximum safe operating temperature for KSB1151YSTSTU?

The KSB1151YSTSTU has a maximum junction temperature (T_J) of 150°C and storage temperature range of −55°C to +150°C. Derating begins above T_C = 25°C per Figure 7: at T_C = 100°C, allowable P_C drops to ~10 W.

Does KSB1151YSTSTU require a heatsink in typical applications?

Yes - KSB1151YSTSTU dissipates up to 20 W at T_C = 25°C. In practice, any application drawing >1 W continuously requires a heatsink. The metal tab (collector) must be mounted to a thermally conductive surface using insulating hardware if isolation is needed.

KSB1151YSTSTU 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):: 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

KSB1151YSTSTU FAQ

1.How can I place an order for KSB1151YSTSTU through Aetrix?

Please submit a Request for Quotation (RFQ) for KSB1151YSTSTU 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 KSB1151YSTSTU reliable?

The price and inventory of KSB1151YSTSTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSB1151YSTSTU is usually 5 days.

3.What payment methods are accepted for KSB1151YSTSTU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSB1151YSTSTU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSB1151YSTSTU?

KSB1151YSTSTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSB1151YSTSTU 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 KSB1151YSTSTU?

For technical support, including KSB1151YSTSTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSB1151YSTSTU requirements.

6.How does Aetrix verify that KSB1151YSTSTU is sourced from the original manufacturer or authorized distributors?

All KSB1151YSTSTU 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 KSB1151YSTSTU meets industry standards.

7.What is the process for return or replacement of KSB1151YSTSTU?

All KSB1151YSTSTU units undergo pre-shipment inspection (PSI). If there is an issue with KSB1151YSTSTU, 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 KSB1151YSTSTU part is unused and in its original packaging.

Return procedure for KSB1151YSTSTU:

1.Submit a request within 90 days.

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

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