Introduction
The TIP122 NPN transistor is a high-power Darlington pair transistor widely used in switching and amplification circuits. It consists of two NPN transistors connected in a Darlington configuration, which provides a very high DC current gain and allows small input currents to control larger output currents. This makes the TIP122 ideal for applications involving motors, relays, solenoids, and high-power LEDs.
With a maximum collector current of 5A and a collector-emitter voltage rating of 100V, the TIP122 is suitable for medium to high power loads. Its ability to handle relatively high voltage and current makes it a popular choice in industrial automation, audio amplifiers, and power regulation circuits. The device is especially useful in projects driven by low-power controllers like Arduino, Raspberry Pi, or PIC microcontrollers, since it requires only a small base current to operate efficiently.
TIP122 NPN Transistor
Packaged in the TO-220 case, the TIP122 can dissipate up to 65W of power with a proper heatsink, ensuring stable operation even under heavy loads. It is commonly found in robotics, home appliances, automotive electronics, and general-purpose switching applications, making it one of the most versatile and cost-effective Darlington transistors available.
TIP122 Pinout
TIP122 Transistor Key Features
- Darlington pair design offering very high current gain.
- Ideal for switching medium to high power loads.
- Requires very low base current for operation.
- Compatible with TTL and microcontroller outputs.
- Robust design suitable for industrial and hobby electronics.
- TO-220 package allows easy mounting with heatsinks.
Specifications/Characteristics of TIP122 NPN Transistor
- Transistor Type: NPN Darlington
- Collector-Emitter Voltage (Vce): 100V
- Collector-Base Voltage (Vcb): 100V
- Emitter-Base Voltage (Veb): 5V
- Collector Current (Ic): 5A continuous
- Peak Collector Current: 8A
- DC Current Gain (hFE): 1000 (typical)
- Power Dissipation (Ptot): 65W (with heatsink)
- Package Type: TO-220
- Operating Temperature Range: -65°C to +150°C
TIP122 Pin Configuration
| Pin# | Pin Name | Pin Description |
|---|---|---|
| 1 | Base | Controls the transistor (input signal). |
| 2 | Collector | Current flows through the load. |
| 3 | Emitter | Connected to ground or return path. |
More Circuit Layouts
Key Applications of TIP122 NPN Transistor
- Relay driver and solenoid driver circuits.
- High-current DC motor controllers.
- Switching regulators and power supplies.
- Audio amplifier output stages.
- High-power LED driving circuits.
- Robotics and industrial control systems.
PNP Complimentary Transistor
TIP127 (PNP Darlington transistor) is the complementary pair of TIP122.
Equivalent Transistors of TIP122
- TIP120 (60V, NPN Darlington)
- TIP121 (80V, NPN Darlington)
- BDW93 (NPN Darlington alternative)
- 2N6284 (high current NPN Darlington)
- MJE802 (similar NPN transistor)
(Pin configuration of some transistors mentioned here may different from TIP122).
Datasheet of TIP122 NPN Transistor
Click the following Button below to download the datasheet of TIP122 Transistor :
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