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onsemi KSB1149YS
- Part No.:
- KSB1149YS
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
KSB1149YS.pdf
- Description:
- TRANS PNP DARL 100V 3A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,077
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Product details
Overview
KSB1149YS 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 control circuits.
For engineers reviewing the KSB1149YS datasheet, pinout, applications, or equivalent options, key selection considerations include its -100 V breakdown rating, Darlington hFE ≥2000 at -1.5 A, low -0.9 V VCE(sat), integrated E-C damper diode, and TO-126 thermal performance with 15 W case-rated dissipation.
Technical Context
The KSB1149YS implements a monolithic PNP Darlington pair with integrated emitter-collector damper diode, enabling inductive load switching without external flyback protection. Its hFE classification (Y-grade: 4000–12000 at -1.5 A) ensures stable current amplification across production lots.
Designed for DC and pulse operation (tON = 0.5 µs, tF = 1 µs), it operates within -55°C to +150°C junction range and supports safe operating area (SOA) compliance up to 100 V and -3 A under pulsed conditions per Figure 4.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -100 V - Withstands 100 V reverse collector-emitter voltage before breakdown, suitable for 48 V and 72 V industrial bus switching |
| IC (DC) | -3 A - Sustains continuous 3 A collector current with adequate heatsinking at TC ≤25°C |
| PC (TC=25°C) | 15 W - Delivers 15 W power dissipation when mounted on heatsink maintaining case temperature at 25°C |
| hFE (Y-grade) | 4000–12000 - High DC current gain enables microampere-level base drive for 1.5–3 A loads |
| VCE(sat) | -0.9 to -1.2 V - Low saturation voltage minimizes conduction loss and self-heating at full load |
| Integrated Diode | Emitter-to-Collector damper - Eliminates need for external flyback diode in relay/inductor driver designs |
Pinout & Package
Package: TO-126 - 3-lead thermally robust plastic power package with metal tab (collector-connected), standardized for vertical mounting and heatsink attachment.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Emitter terminal of Darlington pair | Reference node for base drive; polarity defines PNP operation; connects to positive rail in high-side switch configurations |
| 2 (Collector) | Collector terminal (tab-connected) | Electrically tied to metal tab; must be isolated from heatsink unless circuit ground reference permits |
| 3 (Base) | Control input for Darlington pair | Accepts low-current drive (e.g., -1.5 mA) to switch -1.5 A load; requires current-limiting resistor in series |
Key Features
| Feature | Design Value |
|---|---|
| High hFE Y-classification | Guaranteed 4000–12000 DC current gain at -1.5 A, reducing base drive circuit complexity and power loss |
| Low VCE(sat) | -0.9 V typical saturation voltage at -1.5 A / -1.5 mA drive cuts conduction loss by >30% vs. standard PNP transistors |
| Integrated E-C damper diode | Eliminates discrete flyback diode in solenoid/relay driver PCB layouts, saving board space and BOM count |
| 15 W case power rating | Enables direct heatsink mounting without derating below 100°C case temperature, supporting compact thermal design |
Applications
| Relay Driver Circuit | DC Motor Speed Control |
|---|---|
Use Scenario: Driving 24 V/1 A electromagnetic relays in PLC I/O modules with microcontroller GPIO output. IC Role / Device Role / Timing Role: PNP Darlington switch providing high-current, low-saturation path from 24 V rail to relay coil, with integrated damper diode clamping inductive kick. Use Value: Reduces component count by eliminating external flyback diode while maintaining <1.2 V VCE(sat) at full coil current, minimizing heat generation. | Use Scenario: Linear speed regulation of 36 V brushed DC motors in industrial actuators using analog PWM pre-driver stage. IC Role / Device Role / Timing Role: Medium-power PNP output stage amplifying low-voltage control signal to deliver up to -3 A motor current with minimal voltage drop. Use Value: Leverages 4000+ hFE to accept µA-range base current, easing drive requirements from op-amp or DAC output stages. |
| Unregulated Power Supply Regulator | High-Voltage Lamp Dimmer |
Use Scenario: Series pass element in 72 V input, 48 V/2 A unregulated industrial power supply with thermal foldback protection. IC Role / Device Role / Timing Role: PNP Darlington configured as adjustable series regulator, dissipating up to 15 W at TC=25°C with SOA-compliant operation. Use Value: 15 W case-rated dissipation and -100 V VCEO support wide-input voltage margin and reliable thermal management without forced air. | Use Scenario: Phase-angle dimming control for 100 W halogen lamps in commercial lighting systems using triac-trigger interface. IC Role / Device Role / Timing Role: High-gain PNP switch driving triac gate with precise timing; integrated damper diode suppresses gate noise from lamp inrush transients. Use Value: Fast 0.5 µs turn-on and 1 µs fall time ensure accurate zero-crossing synchronization, improving dimming linearity and EMI performance. |
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 (lower gain), no integrated damper diode | Requires external flyback diode; lower current rating limits use in >2 A loads | Select when cost sensitivity outweighs integration benefit and load current stays ≤2 A |
| BDX53C | VCEO = -100 V, IC = -8 A, hFE = 750–3000, TO-225 package, no integrated damper diode | Larger TO-225 footprint; higher current but lower gain and no E-C diode | Choose for higher current headroom where board space allows larger package and external diode is acceptable |
Compared with MJD127G and BDX53C, the KSB1149YS delivers superior current gain (4000–12000), integrated damper functionality, and optimized TO-126 thermal performance-making it preferred for space-constrained, high-gain, inductive-load switching where reliability and BOM simplification are critical.
Availability
KSB1149YS is available at Aetrix Electronics and suitable for relay drivers, DC motor controllers, and unregulated power supply regulators requiring stable component supply, consistent parametric performance, and long-term industrial availability.
Supply support for KSB1149YS 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 (formerly Fairchild Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, with leadership in power management, analog, and discrete devices.
The KSB1149YS belongs to Fairchild's legacy high-gain PNP Darlington portfolio, engineered for robust medium-power linear and switching applications in industrial controls, power supplies, and electromechanical actuation systems.
FAQ
What is the maximum continuous collector current rating for KSB1149YS?
The KSB1149YS has a maximum DC collector current (IC) rating of -3 A at TA=25°C with appropriate PCB copper area or heatsink. At elevated ambient temperatures, derating applies per the 1.3 W ambient power curve; for sustained -3 A operation, case temperature must be maintained ≤25°C using thermal management per the TO-126 package specifications.
Does KSB1149YS include an integrated damper diode, and how is it connected?
Yes, the KSB1149YS integrates a damper diode between emitter and collector terminals, with cathode at emitter and anode at collector. This configuration clamps inductive kick during turn-off, protecting the transistor in relay and solenoid driver applications without requiring an external diode.
What is the guaranteed hFE range for KSB1149YS at -1.5 A collector current?
The KSB1149YS Y-grade guarantees hFE between 4000 and 12000 when measured at VCE = -2 V and IC = -1.5 A. This high and tightly binned gain reduces base drive requirements and improves consistency in production-scale amplifier and switch designs using the KSB1149YS.
Can KSB1149YS be used in place of KSB1149 without modification?
Yes, KSB1149YS is a Y-grade variant of the KSB1149, sharing identical pinout, package (TO-126), absolute maximum ratings, and electrical characteristics-except for the tighter hFE bin (4000–12000 vs. standard 2000–20000). No PCB or schematic changes are needed when substituting KSB1149YS for KSB1149 in existing designs.
What is the thermal resistance from junction to case (RθJC) for KSB1149YS?
The KSB1149YS exhibits a junction-to-case thermal resistance (RθJC) of approximately 1.67°C/W, calculated from its 15 W maximum collector dissipation at TC=25°C and 150°C maximum junction temperature. This value is consistent with TO-126 packaged Darlington transistors and confirms suitability for direct heatsink mounting with thermal interface material.
KSB1149YS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Bulk
- 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
KSB1149YS FAQ
1.How can I place an order for KSB1149YS through Aetrix?
Please submit a Request for Quotation (RFQ) for KSB1149YS 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 KSB1149YS reliable?
The price and inventory of KSB1149YS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSB1149YS is usually 5 days.
3.What payment methods are accepted for KSB1149YS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSB1149YS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSB1149YS?
KSB1149YS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSB1149YS 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 KSB1149YS?
For technical support, including KSB1149YS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSB1149YS requirements.
6.How does Aetrix verify that KSB1149YS is sourced from the original manufacturer or authorized distributors?
All KSB1149YS 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 KSB1149YS meets industry standards.
7.What is the process for return or replacement of KSB1149YS?
All KSB1149YS units undergo pre-shipment inspection (PSI). If there is an issue with KSB1149YS, 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 KSB1149YS part is unused and in its original packaging.
Return procedure for KSB1149YS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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