The MMBT2222A is an NPN small signal transistor housed in a compact SOT-23 package. It features high gain, low saturation voltage, and excellent high-speed switching performance, making it ideal for signal amplification, switching control, and driving low-power loads. With a maximum collector-emitter voltage of 40V and a continuous collector current of up to 600mA, it offers strong versatility and is widely used in communication, consumer electronics, and industrial control applications.
As a surface-mount replacement for many through-hole transistors, the MMBT2222A is well-suited for automated manufacturing and PCB space optimization.
B (Base): The control terminal used to turn the transistor on or off.
E (Emitter): The terminal through which current exits (in NPN configuration).
C (Collector): The main output terminal where the majority of current flows.
| Parameter | Value |
| Transistor Type | NPN |
| Package | SOT-23-3 |
| Collector-Emitter Voltage | 40 V |
| Collector-Base Voltage | 75 V |
| Emitter-Base Voltage | 6 V |
| Collector Current | 600 mA |
| Vce Saturation (Max) @ Ib, Ic | 1V @ 50mA, 500mA |
| Collector Cutoff Current | 10nA (ICBO) |
| Power | 250 mW |
| Transition Frequency | 250 MHz |
| Saturation Voltage | Max 0.3 V at I<sub>C</sub> = 150 mA |
| Operating Temperature Range | -55°C ~ 150°C |
Power Dissipation of 300mW
Epitaxial Planar Die Construction
High Stability and High Reliability
Complementary PNP Type Available (MMBT2907A)
General Purpose
Compliant to RoHS, REACH, Conflict Minerals
MMBT2222A Applications
Signal Amplification
Switching Circuits
Pulse and Logic Circuits
Voltage Level Shifting
Driver Stages
Battery-Powered Devices
The MMBT2222A has several equivalent variants within the same series, often differing by manufacturer-specific suffixes or packaging details. Common equivalents include MMBT2222A-7-F, MMBT2222A-215, MMBT2222A-TP, MMBT2222A-13-F, and MMBT2222A-13-TAPE.
ON Semiconductor (now rebranded as onsemi) is one of the world’s leading semiconductor manufacturers, specializing in high-performance and energy-efficient electronic components and solutions. As a key producer of small signal transistors like the MMBT2222A, onsemi employs advanced manufacturing technologies and strict quality control systems to ensure exceptional performance and high reliability across its product lineup.
The MMBT2222A features a SOT-23 package, a widely used small surface-mount package ideal for high-density PCB designs. Compact in size with good thermal performance, the SOT-23 package supports automated assembly and helps save board space. It typically includes three terminals corresponding to the transistor’s Base (B), Emitter (E), and Collector (C). This package is well-suited for small signal amplification and switching applications, making it a popular choice in modern electronic devices.
When connecting the MMBT2222A, it's important to first understand its three pin functions. In typical usage, the emitter is connected to ground, the collector is connected to the load and then to the positive power supply, and the base is connected to a control signal through a current-limiting resistor.
When the base voltage is approximately 0.7V higher than the emitter, the transistor turns on, allowing current to flow from the collector to the emitter, thereby driving the external load. If the base voltage is below the threshold, the transistor remains off, and the path between collector and emitter is open. This configuration is commonly used in motor control, LED switching, and signal amplification applications.
The MMBT2222A is a general-purpose NPN bipolar junction transistor (BJT) in a compact SOT-23 surface-mount package. It is widely used for low-power switching and signal amplification.
Typically:
Emitter to ground
Collector to load (then to Vcc)
Base through a resistor to the control signal
One of the primary manufacturers is onsemi (formerly ON Semiconductor), known for reliable and high-performance discrete semiconductors.
