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onsemi KSB1149OSTU
- Part No.:
- KSB1149OSTU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
KSB1149OSTU.pdf
- Description:
- TRANS PNP DARL 100V 3A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,682
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Product details
Overview
KSB1149OSTU 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 15 W collector dissipation at TC=25°C, with built-in emitter-collector damper diode; used in high-gain, medium-power linear and switching applications such as relay drivers and power supply error amplifiers.
For engineers reviewing the KSB1149OSTU datasheet, pinout, applications, or equivalent options, key selection factors include its Darlington hFE ≥2000 at -1.5 A, low VCE(sat) of -0.9 V, integrated E-C damper diode, TO-126 thermal performance, and -150°C junction temperature rating.
Technical Context
The KSB1149OSTU implements a monolithic PNP Darlington pair with integrated emitter-collector damper diode, enabling inductive load switching without external flyback protection. Its high DC current gain (hFE = 2000–20000, classified O/Y/G) and low saturation voltages (VCE(sat) ≤ -1.2 V, VBE(sat) ≤ -2.0 V at -1.5 A/-1.5 mA) support efficient base drive in medium-power analog and switching circuits.
Thermal design relies on case-mounted heat sinking: PC = 15 W at TC = 25°C, derating linearly to zero at TC = 175°C. Safe operating area (SOA) is defined for pulsed operation (PW ≤ 10 ms, duty ≤ 50%) and DC conditions, with forward-bias SOA limited by secondary breakdown and thermal constraints.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -100 V - supports high-voltage PNP switching up to 100 V reverse bias across C-E |
| IC (DC) | -3 A - delivers continuous collector current suitable for relay coils and medium-power regulators |
| hFE (min) | 2000 @ -1.5 A - enables low-base-current drive for efficient control in linear amplifiers and switch drivers |
| VCE(sat) | -0.9 V max @ -1.5 A/-1.5 mA - minimizes conduction loss and self-heating in saturated-switching applications |
| PC (TC=25°C) | 15 W - requires heatsink mounting for sustained power dissipation; TO-126 case enables direct thermal coupling |
| Integrated Diode | Emitter-to-collector damper - eliminates need for external flyback diode when driving inductive loads |
| TJ max | 150 °C - defines maximum allowable junction temperature under steady-state or pulsed thermal stress |
Pinout & Package
Package: TO-126, through-hole, thermally enhanced plastic case with metal tab for heatsink attachment. Dimensions: 16.10 × 13.06 × 4.2 mm (L×W×H), mounting hole ø3.20 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Emitter terminal of Darlington pair | Connected to system ground or low-side return; carries full load current and interfaces with damper diode cathode |
| 2 (Collector) | Collector terminal of Darlington pair | Connected to high-side load (e.g., relay coil anode); damper diode anode tied internally to this pin |
| 3 (Base) | Control input for Darlington pair | Receives low-current drive signal; high hFE allows µA-level base current to switch amps of collector current |
Key Features
| Feature | Design Value |
|---|---|
| Monolithic Darlington structure | Single-die integration of driver and output transistors ensures matched thermal behavior and stable hFE over temperature |
| Low VCE(sat) | -0.9 V typical at -1.5 A reduces power loss and improves efficiency in saturated-switching topologies |
| Built-in E-C damper diode | Eliminates discrete flyback diode requirement, saving PCB area and improving reliability in inductive load switching |
| High power dissipation capability | 15 W at TC = 25°C enables use in thermally demanding linear regulators and motor drivers without oversized heatsinks |
| TO-126 mechanical robustness | Sturdy leadframe and metal tab ensure reliable mechanical mounting and long-term thermal interface stability |
Applications
| Relay Driver Circuits | Linear Voltage Regulators |
|---|---|
Use Scenario: Driving 12–24 V DC electromagnetic relays with coil currents up to 2.5 A in industrial PLC I/O modules. IC Role / Device Role / Timing Role: PNP Darlington switch providing high-current, low-saturation switching with integrated flyback protection. Use Value: Eliminates external flyback diode and reduces base drive requirements due to hFE ≥2000, simplifying BOM and layout. | Use Scenario: Pass transistor in adjustable negative linear regulators delivering up to -2 A at -15 V output. IC Role / Device Role / Timing Role: High-gain, high-power PNP pass element controlling output voltage via feedback loop. Use Value: Low VCE(sat) minimizes dropout voltage and thermal load; TO-126 package enables direct heatsink mounting. |
| DC Motor Speed Control | Power Supply Error Amplifiers |
Use Scenario: Low-frequency PWM-driven H-bridge high-side switch for brushed DC motors in automotive accessory systems. IC Role / Device Role / Timing Role: Medium-speed PNP Darlington switch handling bidirectional inductive energy recovery via internal damper diode. Use Value: Integrated E-C diode clamps inductive kickback during turn-off, preventing voltage spikes that could damage upstream controllers. | Use Scenario: Error amplifier stage in isolated flyback or forward converter feedback networks requiring high open-loop gain and stable bias. IC Role / Device Role / Timing Role: High-hFE, low-noise PNP transistor amplifying optocoupler output to drive PWM controller reference input. Use Value: hFE ≥2000 ensures precise current mirroring and minimal offset drift over temperature and load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD127G | VCEO = -100 V, IC = -2 A, hFE = 1000–4000, no integrated damper diode, DPAK package | Requires external flyback diode; lower current rating limits use in >2 A relay/motor loads | Select when surface-mount assembly is required and external diode integration is acceptable |
| KSC2383YTA | PNP single transistor (not Darlington), VCEO = -160 V, IC = -1 A, hFE = 200–400, TO-92 package | Lacks Darlington gain and integrated diode; unsuitable for low-base-drive or inductive switching roles | Select only for low-current, high-voltage linear amplification where Darlington benefits are unnecessary |
Compared with MJD127G and KSC2383YTA, the KSB1149OSTU uniquely combines TO-126 thermal capability, integrated E-C damper, and Darlington hFE ≥2000-making it optimal for medium-power, inductive-load switching where board space, base drive simplicity, and thermal margin are critical.
Availability
KSB1149OSTU is available at Aetrix Electronics and suitable for relay driver circuits, linear voltage regulators, DC motor speed control, and power supply error amplifier designs requiring stable component supply and long-lifecycle availability.
Supply support for KSB1149OSTU 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, high-performance silicon solutions for automotive, industrial, cloud computing, and IoT applications.
The KSB1149OSTU belongs to ON Semiconductor's legacy bipolar power transistor family, designed specifically for high-gain, medium-power linear and switching applications requiring integrated protection and robust thermal performance.
FAQ
What is the maximum continuous collector current rating for KSB1149OSTU?
The KSB1149OSTU has a maximum DC collector current (IC) rating of -3 A at TA = 25°C. This rating assumes proper heatsinking and operation within the safe operating area (SOA). At higher ambient temperatures or without adequate thermal management, derating applies per the published power dissipation curve.
Does KSB1149OSTU include an integrated damper diode, and how is it connected?
Yes, the KSB1149OSTU includes a monolithically integrated damper diode between emitter and collector. The diode anode is connected to the collector terminal (Pin 2), and the cathode is connected to the emitter terminal (Pin 1), enabling automatic clamping of inductive kickback during turn-off without external components.
What is the minimum DC current gain (hFE) of KSB1149OSTU at -1.5 A collector current?
The minimum DC current gain (hFE) of KSB1149OSTU is 2000 at VCE = -2 V and IC = -1.5 A, per the "O" classification bin. This high gain allows the KSB1149OSTU to be driven with very low base current-typically -1.5 mA-making it ideal for microcontroller-compatible switching interfaces.
Can KSB1149OSTU be used in surface-mount designs?
No, the KSB1149OSTU is packaged exclusively in the through-hole TO-126 outline and is not available in surface-mount variants. Its metal tab and leadframe geometry require hole-mounting and mechanical heatsink attachment. For SMT alternatives, consider MJD127G (DPAK) or FZT790A (SOT-223), though neither integrates a damper diode.
What is the absolute maximum junction temperature for KSB1149OSTU?
The absolute maximum junction temperature (TJ) for KSB1149OSTU is 150°C. Operation beyond this limit risks permanent degradation of the Darlington structure and integrated damper diode. Thermal design must ensure junction temperature remains below 150°C under worst-case power dissipation and ambient conditions.
KSB1149OSTU 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:
- 2000 @ 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
KSB1149OSTU FAQ
1.How can I place an order for KSB1149OSTU through Aetrix?
Please submit a Request for Quotation (RFQ) for KSB1149OSTU 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 KSB1149OSTU reliable?
The price and inventory of KSB1149OSTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSB1149OSTU is usually 5 days.
3.What payment methods are accepted for KSB1149OSTU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSB1149OSTU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSB1149OSTU?
KSB1149OSTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSB1149OSTU 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 KSB1149OSTU?
For technical support, including KSB1149OSTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSB1149OSTU requirements.
6.How does Aetrix verify that KSB1149OSTU is sourced from the original manufacturer or authorized distributors?
All KSB1149OSTU 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 KSB1149OSTU meets industry standards.
7.What is the process for return or replacement of KSB1149OSTU?
All KSB1149OSTU units undergo pre-shipment inspection (PSI). If there is an issue with KSB1149OSTU, 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 KSB1149OSTU part is unused and in its original packaging.
Return procedure for KSB1149OSTU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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