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onsemi KSB1149YSTU
- Part No.:
- KSB1149YSTU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
KSB1149YSTU.pdf
- Description:
- TRANS PNP DARL 100V 3A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,684
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Product details
Overview
KSB1149YSTU from ON Semiconductor (formerly Fairchild) is a PNP silicon Darlington transistor in TO-126 package, rated for -100 V VCEO, -3 A DC collector current, and 1.3 W power dissipation at TA=25°C, with built-in emitter-collector damper diode; used in high-gain switching applications such as relay drivers and lamp controls.
For engineers reviewing the KSB1149YSTU datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed hFE ≥2000 at IC=−1.5 A, low VCE(sat) ≤−1.2 V, integrated E-C damper diode, TO-126 thermal performance, and −150°C maximum junction temperature.
Technical Context
This Darlington pair integrates two PNP transistors in cascade to achieve high DC current gain while maintaining single-package simplicity. It operates with negative-polarity biasing, requires base current limiting, and relies on its internal damper diode to suppress inductive kickback during turn-off in relay or solenoid loads.
The device's safe operating area (SOA) is defined by both dissipation-limited and second-breakdown-limited boundaries, with derating required above 25°C case temperature. Its pulse capability supports ICP=−5 A for ≤10 ms at ≤50% duty cycle, enabling short-duration surge handling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −100 V: Maximum sustainable collector-emitter voltage under open-base conditions; defines off-state blocking capability in high-side switch configurations. |
| IC (DC) | −3 A: Continuous collector current rating; sets steady-state load drive capacity without thermal runaway at TA=25°C. |
| hFE1 | 2000–5000: Minimum/maximum DC current gain at VCE=−2 V, IC=−1.5 A; ensures reliable base drive reduction in linear or saturated switching. |
| VCE(sat) | −0.9 to −1.2 V: Collector-emitter saturation voltage at IC=−1.5 A, IB=−1.5 mA; directly determines conduction loss and heat generation in on-state. |
| PC (TA) | 1.3 W: Maximum power dissipation at ambient 25°C; defines heatsinking requirement for continuous operation without derating. |
| Integrated Diode | Emitter-to-collector damper diode: Suppresses inductive voltage spikes during turn-off; eliminates need for external flyback diode in relay/solenoid circuits. |
Pinout & Package
Package: TO-126 - thermally robust through-hole package with metal tab for heatsink mounting; pin 1 = Emitter, pin 2 = Collector, pin 3 = Base; tab electrically connected to collector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current source terminal for PNP Darlington | Connected to positive rail in high-side switch; carries full load current and must be routed with low-inductance path. |
| 2 (Collector) | Current sink terminal, tied to metal tab | Electrically bonded to package tab; requires insulated mounting if tab is heatsinked to chassis ground. |
| 3 (Base) | Control input for Darlington pair | Receives low-current drive (e.g., microcontroller GPIO via series resistor); base current ≈ IC/hFE for saturation. |
Key Features
| Feature | Design Value |
|---|---|
| High DC current gain | hFE ≥2000 at IC=−1.5 A enables microampere-level base drive for ampere-level loads, reducing driver-stage complexity. |
| Low VCE(sat) | ≤−1.2 V at rated current minimizes conduction loss and self-heating, supporting higher efficiency in battery-powered or thermally constrained designs. |
| Integrated E-C damper diode | Eliminates discrete flyback diode in inductive load switching, saving PCB area and assembly cost while ensuring consistent clamping behavior. |
| TO-126 thermal design | Metal tab allows direct heatsink attachment; 15 W PC at TC=25°C supports short-term overload handling when properly mounted. |
Applications
| Relay Driver Circuits | Lamp and LED Array Control |
|---|---|
Use Scenario: Driving 12 V/24 V electromagnetic relays in industrial PLC output modules. IC Role / Device Role / Timing Role: High-gain PNP Darlington switch providing isolated high-current sink path with fast turn-on (tON ≤0.5 µs) and controlled turn-off. Use Value: Eliminates need for external flyback diode due to built-in E-C damper, reduces component count, and ensures reliable contactor de-energization without voltage overshoot. | Use Scenario: Switching incandescent or halogen lamps in automotive interior lighting or signage systems. IC Role / Device Role / Timing Role: High-current, low-saturation-voltage switch managing inrush current and steady-state load; handles surge up to −5 A pulses. Use Value: Low VCE(sat) limits power loss during extended on-time, while integrated damper prevents filament stress from inductive transients during dimming transitions. |
| Solenoid Actuator Interface | DC Motor Brake Control |
Use Scenario: Controlling 24 V DC solenoids in HVAC valve actuators or vending machine mechanisms. IC Role / Device Role / Timing Role: Darlington-based high-side switch delivering −3 A DC with fast storage time (tSTG ≤2 µs) to minimize release delay. Use Value: Guaranteed hFE ≥2000 ensures stable turn-on even with aging or temperature drift in base drive circuitry, improving long-term reliability. | Use Scenario: Dynamic braking of small DC motors in robotics or power tools by shorting motor terminals through a switched path. IC Role / Device Role / Timing Role: High-current PNP switch connecting motor armature to ground (via complementary NPN or direct low-side configuration), activated during deceleration. Use Value: −100 V VCEO rating accommodates back-EMF spikes up to 80 V, and TO-126 thermal mass absorbs brief brake-energy surges without thermal shutdown. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BDX53C | VCEO = −100 V, IC = −8 A, hFE = 750–2500, no integrated damper diode, TO-126 package | Higher current rating but lower minimum hFE; requires external flyback diode for inductive loads | Select when higher continuous current is needed and board space allows external diode placement |
| MJD127 | VCEO = −100 V, IC = −2 A, hFE = 1000–4000, no integrated damper diode, TO-220 package | Lower IC rating and different package; lacks E-C damper; higher thermal resistance than TO-126 at same mounting condition | Select when TO-220 footprint is preferred and inductive load energy is low enough to tolerate external clamping |
Compared with BDX53C and MJD127, the KSB1149YSTU offers superior current gain stability and built-in transient suppression-critical for compact relay and solenoid interfaces where layout space and reliability under repetitive switching are prioritized over raw current headroom.
Availability
KSB1149YSTU is available at Aetrix Electronics and suitable for relay driver circuits, lamp control systems, solenoid actuator interfaces, and DC motor brake control requiring stable component supply across industrial automation, automotive subsystems, and appliance manufacturing.
Supply support for KSB1149YSTU 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
ON Semiconductor is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, communications, computing, and consumer markets.
The KSB1149YSTU belongs to ON Semiconductor's legacy bipolar power transistor family, designed specifically for high-gain, medium-power linear and switching applications in industrial control and electromechanical interface circuits.
FAQ
What is the maximum continuous collector current rating for KSB1149YSTU?
The KSB1149YSTU has a maximum DC collector current rating of −3 A at TA = 25°C. This value assumes proper PCB copper area and ambient airflow; derating is required at higher temperatures per the published power derating curve. The KSB1149YSTU can sustain −5 A in pulsed mode (PW ≤10 ms, duty cycle ≤50%), making it suitable for intermittent high-load events.
Does KSB1149YSTU include an integrated damper diode, and how is it connected?
Yes, the KSB1149YSTU includes a built-in damper diode connected between emitter and collector (anode to emitter, cathode to collector). This configuration clamps inductive kickback during turn-off, eliminating the need for an external flyback diode in relay or solenoid drive circuits. The diode is monolithically integrated and shares the same thermal environment as the Darlington pair.
What is the guaranteed DC current gain (hFE) range for KSB1149YSTU at typical operating conditions?
The KSB1149YSTU is classified with hFE1 ranging from 2000 to 5000 at VCE = −2 V and IC = −1.5 A. This minimum gain ensures predictable base drive requirements across production lots and temperature ranges. The actual hFE may reach up to 20000 in higher-grade variants, but the KSB1149YSTU specifically meets the "O" classification band.
Can KSB1149YSTU be used in high-side switch configurations, and what are the base drive considerations?
Yes, the KSB1149YSTU is a PNP Darlington optimized for high-side switching. Base drive must be referenced to the emitter (positive rail), typically using a current-limiting resistor from a logic-level control signal. For IC = −1.5 A and hFE = 2000, base current ≈ −750 µA is sufficient; however, −1.5 mA is recommended to ensure saturation across temperature and process variation.
What is the thermal resistance from junction to case (RθJC) for KSB1149YSTU in TO-126 package?
The KSB1149YSTU exhibits a junction-to-case thermal resistance of approximately 1.7°C/W when mounted with proper thermal interface material to a heatsink. This value is derived from its 15 W power dissipation rating at TC = 25°C (PC = (TJ − TC) / RθJC). Actual RθJC depends on mounting pressure and surface flatness, and must be validated in final mechanical design.
KSB1149YSTU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Transistor Type:
- PNP - Darlington
- Current - Collector (Ic) (Max):
- 3 A
- Voltage - Collector Emitter Breakdown (Max):
- 100 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.2V @ 1.5mA, 1.5A
- Current - Collector Cutoff (Max):
- 10µA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 4000 @ 1.5A, 2V
- Power - Max:
- 1.3 W
- Frequency - Transition:
- -
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126-3
KSB1149YSTU FAQ
1.How can I place an order for KSB1149YSTU through Aetrix?
Please submit a Request for Quotation (RFQ) for KSB1149YSTU 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 KSB1149YSTU reliable?
The price and inventory of KSB1149YSTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSB1149YSTU is usually 5 days.
3.What payment methods are accepted for KSB1149YSTU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSB1149YSTU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSB1149YSTU?
KSB1149YSTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSB1149YSTU 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 KSB1149YSTU?
For technical support, including KSB1149YSTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSB1149YSTU requirements.
6.How does Aetrix verify that KSB1149YSTU is sourced from the original manufacturer or authorized distributors?
All KSB1149YSTU 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 KSB1149YSTU meets industry standards.
7.What is the process for return or replacement of KSB1149YSTU?
All KSB1149YSTU units undergo pre-shipment inspection (PSI). If there is an issue with KSB1149YSTU, 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 KSB1149YSTU part is unused and in its original packaging.
Return procedure for KSB1149YSTU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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