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onsemi KSB1149OS
- Part No.:
- KSB1149OS
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
KSB1149OS.pdf
- Description:
- TRANS PNP DARL 100V 3A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,464
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Product details
Overview
KSB1149OS 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 KSB1149OS datasheet, pinout, applications, or equivalent options, key selection criteria include its -100 V breakdown rating, -1.2 V VCE(sat) at -1.5 A, hFE ≥2000, integrated E-C damper diode, and TO-126 thermal performance under continuous and pulsed operation.
Technical Context
The KSB1149OS 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, depending on classification) supports low-base-drive designs while maintaining robust saturation behavior (VCE(sat) ≤ -1.2 V at -1.5 A).
Thermal design leverages the TO-126 package's 15 W power dissipation capability at case temperature TC = 25°C, with derating to zero at 150°C junction temperature; safe operating area (SOA) is defined for both DC and pulsed conditions (PW ≤ 10 ms, duty cycle ≤ 50%).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -100 V - Supports high-voltage PNP switching up to 100 V reverse bias across collector-emitter. |
| IC (DC) | -3 A - Sustains continuous 3 A sink current in linear or saturated operation. |
| PC (TC=25°C) | 15 W - Enables high-power dissipation when mounted on heatsink with controlled case temperature. |
| hFE (IC = -1.5 A) | ≥2000 - Reduces required base drive current by >20× vs. single PNP, easing driver design. |
| VCE(sat) | -1.2 V max at IC = -1.5 A, IB = -1.5 mA - Limits conduction loss to <1.8 W at rated current. |
| Integrated Diode | Emitter-to-collector damper - Eliminates need for external flyback diode in relay/inductor drive. |
| tON/tF | 0.5 µs / 1 µs - Supports switching frequencies up to ~300 kHz in non-critical timing applications. |
Pinout & Package
Package: TO-126 (3-lead, through-hole, thermally enhanced plastic). Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base. Mounting tab (Collector-connected) enables direct heatsinking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current source terminal for PNP Darlington | Connected to positive rail in high-side switch configurations; carries full load current. |
| 2 (Collector) | Current sink terminal; internally tied to mounting tab | Electrically and thermally connected to heatsink; requires insulation if heatsink is grounded. |
| 3 (Base) | Control input for Darlington pair | Low-current input (≤1.5 mA typical) drives high-current output; requires current-limiting resistor. |
Key Features
| Feature | Design Value |
|---|---|
| High hFE (2000–20000) | Enables microcontroller-level base drive (e.g., 1–2 mA) to switch 1.5–3 A loads reliably. |
| Low VCE(sat) (-1.2 V max) | Reduces power loss and self-heating during saturation, improving efficiency in linear regulators and lamp drivers. |
| Integrated E-C damper diode | Eliminates discrete flyback diode and associated PCB space, BOM count, and layout complexity in inductive load circuits. |
| 15 W power dissipation (TC=25°C) | Supports high-current operation with minimal heatsink volume when case temperature is actively managed. |
Applications
| Relay Drivers | Linear Regulator Pass Transistors |
|---|---|
Use Scenario: Driving 12 V/24 V electromagnetic relays with coil inductance >100 mH in industrial PLC output modules. IC Role / Device Role / Timing Role: High-gain PNP Darlington switch providing low-base-current, high-current sinking capability with integrated flyback protection. Use Value: Eliminates external flyback diode and reduces base drive requirements by >10× versus standard PNP transistors. | Use Scenario: As pass element in negative-output adjustable linear regulators delivering up to -2.5 A at -5 V to -30 V. IC Role / Device Role / Timing Role: Series-pass transistor regulating output voltage via base-controlled emitter-follower configuration. Use Value: Low VCE(sat) minimizes dropout voltage and thermal stress under full load, extending regulator stability. |
| Lamp & Solenoid Drivers | DC Motor Brake Circuits |
Use Scenario: Controlling incandescent lamps (up to 30 W) and 24 V solenoids in HVAC actuators and vending machine dispensers. IC Role / Device Role / Timing Role: Medium-power PNP switch interfacing microcontroller GPIO to resistive/inductive loads. Use Value: Built-in damper diode prevents voltage spikes during turn-off, protecting MCU I/O and reducing EMI. | Use Scenario: Providing dynamic braking for 24 V brushed DC motors in automated gate operators and conveyor systems. IC Role / Device Role / Timing Role: High-current PNP switch shorting motor terminals to ground during deceleration. Use Value: High IC rating (-3 A DC) and SOA support repeated braking pulses without thermal runaway. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP Darlington transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD112G | VCEO = -100 V, IC = -2 A, no integrated damper diode, TO-220 package | Requires external flyback diode; higher thermal mass but lower gain (hFE min = 1000) | Choose when higher ruggedness and heatsink compatibility outweigh need for integrated diode. |
| KSA1220AYS | VCEO = -120 V, IC = -2 A, hFE = 1000–4000, TO-92 package, no damper diode | Lower power (0.6 W), not suitable for >500 mA loads; lacks integrated protection | Use only in low-current signal amplification or biasing where TO-92 footprint is mandatory. |
Compared with MJD112G and KSA1220AYS, the KSB1149OS uniquely combines -3 A current capability, integrated E-C damper diode, and TO-126 thermal performance-making it optimal for compact, high-reliability medium-power switching where board space and component count are constrained.
Availability
KSB1149OS is available at Aetrix Electronics and suitable for relay drivers, linear regulator pass elements, lamp/solenoid controls, and DC motor brake circuits requiring stable component supply and long-term industrial availability.
Supply support for KSB1149OS 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, scalable solutions for automotive, industrial, cloud, medical, and edge applications.
The KSB1149OS 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 handling in industrial control hardware.
FAQ
What is the maximum continuous collector current rating for the KSB1149OS?
The KSB1149OS is rated for -3 A DC collector current at TA = 25°C. Derating applies above ambient temperature; actual usable current depends on heatsinking and case temperature. At TC = 25°C, the device supports up to -3 A continuously with proper thermal management. The KSB1149OS datasheet specifies this limit under absolute maximum ratings and confirms it in electrical characteristics tables.
Does the KSB1149OS include an integrated damper diode, and how is it connected?
Yes, the KSB1149OS 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. The diode is monolithically integrated and shares the same thermal path as the Darlington pair, ensuring coordinated reliability. This feature is explicitly stated in the KSB1149OS product summary and confirmed in the "Features" section of its datasheet.
What is the minimum DC current gain (hFE) of the KSB1149OS at IC = -1.5 A?
The KSB1149OS has a minimum hFE of 2000 at VCE = -2 V and IC = -1.5 A, per the "hFE1" specification in its datasheet. This value applies to the standard "O" classification grade. Higher-gain variants (Y, G) offer minima of 4000 and 6000 respectively. All values are measured under pulsed conditions to avoid self-heating effects, and the KSB1149OS maintains this gain across its specified operating range.
Can the KSB1149OS be used in surface-mount designs?
No, the KSB1149OS is packaged exclusively in the through-hole TO-126 outline and is not available in surface-mount variants. Its leadframe and thermal tab are designed for vertical mounting with heatsink attachment via the collector-connected tab. Attempting SMT reflow would damage the package and void specifications. For SMT-compatible alternatives, engineers should evaluate devices like the NSS12201CF8T1G (SOT-89) or MMDT3906 (SOT-363), though neither offers integrated damper diode or equivalent power rating. The KSB1149OS remains a through-hole solution by design.
What is the safe operating area (SOA) limitation for the KSB1149OS at TC = 25°C?
At TC = 25°C, the KSB1149OS SOA is bounded by three constraints: DC dissipation (15 W), second breakdown (defined in Figure 4 of its datasheet), and peak pulse limits (ICP = -5 A, PW ≤ 10 ms, duty ≤ 50%). The SOA curve shows that at VCE = -40 V, maximum continuous IC is ~0.375 A; at VCE = -10 V, it rises to ~1.5 A. These boundaries ensure reliable operation without thermal runaway or secondary breakdown. The KSB1149OS datasheet provides full SOA graphs for both DC and pulsed conditions.
KSB1149OS 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:
- 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
KSB1149OS FAQ
1.How can I place an order for KSB1149OS through Aetrix?
Please submit a Request for Quotation (RFQ) for KSB1149OS 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 KSB1149OS reliable?
The price and inventory of KSB1149OS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSB1149OS is usually 5 days.
3.What payment methods are accepted for KSB1149OS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSB1149OS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSB1149OS?
KSB1149OS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSB1149OS 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 KSB1149OS?
For technical support, including KSB1149OS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSB1149OS requirements.
6.How does Aetrix verify that KSB1149OS is sourced from the original manufacturer or authorized distributors?
All KSB1149OS 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 KSB1149OS meets industry standards.
7.What is the process for return or replacement of KSB1149OS?
All KSB1149OS units undergo pre-shipment inspection (PSI). If there is an issue with KSB1149OS, 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 KSB1149OS part is unused and in its original packaging.
Return procedure for KSB1149OS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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