TIP105R STMicroelectronics Transistor Darlington Pair (Transistor Outline, Vertical) In Stock
The STMicroelectronics TIP105R is a PNP Darlington power transistor rated at 8 A collector current, 60 V collector-emitter voltage, and a minimum DC current gain (hFE) of 2000, housed in a TO-220AB package. Its integrated freewheeling diode and base-emitter resistors simplify driver circuit design for inductive loads such as motors, relays, and solenoids.
- Manufacturer
- STMicroelectronics
- Package
- Transistor Outline, Vertical
- Pin Count
- 3
- Lifecycle
- OBSOLETE
- Datasheet
- TIP105R Datasheet PDF
- Category
- Transistor Darlington Pair
- Temp Range
- ?°C to 150.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- High DC current gain of minimum 2000 hFE from the monolithic Darlington pair configuration enables direct drive from low-current logic or microcontroller outputs without additional pre-driver stages
- Integrated freewheeling diode and base-emitter bias resistors eliminate external components, reducing BOM count and PCB area in relay, solenoid, and motor switching circuits
- Robust 8 A / 60 V PNP power rating in a TO-220AB package with screw-mount metal tab allows easy heatsinking for continuous high-current switching applications
Applications
The TIP105R is commonly used as a high-side PNP switching element in relay-driver boards, solenoid actuators, and small DC motor controllers where a microcontroller I/O pin must switch loads drawing up to 8 A at voltages up to 60 V. Its Darlington gain of 2000 hFE minimum allows direct drive from standard 5 V or 3.3 V logic with base currents as low as a few milliamps, making it suitable for PLC output modules and industrial automation panels. The integrated suppression diode also makes it a compact solution for chopper-mode motor speed controllers that generate inductive back-EMF spikes.
Specifications
| YTEOL | 0 |
| Collector Current-Max (IC) | 8A |
| Collector-Emitter Voltage-Max | 60V |
| Configuration | DARLINGTON WITH BUILT-IN DIODE AND RESISTOR |
| DC Current Gain-Min (hFE) | 2000 |
| JEDEC-95 Code | TO-220AB |
| JESD-30 Code | R-PSFM-T3 |
| JESD-609 Code | e3 |
| Number of Elements | 1 |
| Package Body Material | PLASTIC/EPOXY |
| Package Shape | RECTANGULAR |
| Package Style | FLANGE MOUNT |
| Polarity/Channel Type | PNP |
| Qualification Status | Not Qualified |
| Surface Mount | NO |
| Terminal Finish | Matte Tin (Sn) |
| Terminal Form | THROUGH-HOLE |
| Terminal Position | SINGLE |
| Transistor Application | SWITCHING |
| Transistor Element Material | SILICON |
| Package | Transistor Outline, Vertical |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
Why does the TIP105R's Darlington configuration with hFE ≥ 2000 allow direct connection to a microcontroller GPIO pin?
A Darlington pair multiplies the gain of two transistors together; with a minimum hFE of 2000, switching 8 A of collector current requires only 4 mA of base drive current (8 A ÷ 2000 = 4 mA). Most microcontroller GPIO pins source or sink 8–20 mA at 3.3 V or 5 V, which is more than enough to fully saturate the TIP105R without a separate pre-driver IC or buffer transistor in the circuit.
What advantage does the TIP105R's integrated freewheeling diode provide when switching inductive loads such as relays or solenoids?
When an inductive load is de-energized, the collapsing magnetic field generates a back-EMF voltage spike that can reach several times the supply voltage in microseconds. The TIP105R's built-in freewheeling diode provides a low-impedance recirculation path for this inductive energy, clamping the voltage spike before it can exceed the 60 V collector-emitter rating and damage the transistor or adjacent circuitry, eliminating the need for an external flyback diode and reducing component count by 1 per output channel.
How should a TIP105R be heatsinked when switching loads near its 8 A continuous rating in a 25°C ambient environment?
The TO-220AB package has a junction-to-case thermal resistance of approximately 3.1°C/W. At 8 A with a saturation voltage of roughly 1.4 V, the device dissipates about 11.2 W. With a maximum junction temperature of 150°C and a 25°C ambient, the total allowable thermal resistance from junction to ambient is (150 − 25) / 11.2 ≈ 11.2°C/W. Subtracting the 3.1°C/W junction-to-case resistance leaves roughly 8°C/W for the heatsink plus interface material, which corresponds to a medium-size extruded aluminum heatsink.
When is the TIP105R a lower-cost PNP alternative to the TIP125 or TIP127 for a 60 V motor control design?
The TIP105R is directly substitutable for the TIP125 (60 V, 5 A) when the load current does not exceed 8 A, and it is a viable alternative to the TIP127 (100 V, 5 A) for 60 V applications where the higher voltage rating of the TIP127 is unnecessary. In such cases, the TIP105R typically offers a similar or lower unit price while providing a higher 8 A continuous current rating, meaning fewer parallel devices are needed in high-current driver stages, reducing total BOM cost per output channel.
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