The 2N3053 is a classic, medium-power silicon planar NPN bipolar junction transistor (BJT) encapsulated in a rugged metal TO-39 can package. Engineered for general-purpose amplifier stages, medium-speed switching, and driver circuits, the 2N3053 delivers a collector current capacity up to 700mA, a collector-emitter breakdown voltage of 40V, and a high transition frequency (f_T) of 100MHz. It is widely used in audio preamplifier drivers, relay and solenoid switching, power supply pass stages, and educational electronics laboratories.

Specifications

• Brand / Manufacturer: Central Semiconductor / STMicroelectronics / Industry Standard
• Part Number: 2N3053
• Transistor Type: Medium-Power NPN Bipolar Junction Transistor (BJT)
• Collector-Emitter Breakdown Voltage (V_CEO): 40V
• Collector-Base Voltage (V_CBO): 60V
• Emitter-Base Voltage (V_EBO): 5.0V
• Continuous Collector Current (I_C): 700mA (0.7A)
• DC Current Gain (h_FE): 50 to 250 (at I_C = 150mA, V_CE = 10V) / Min 25 (at I_C = 150mA, V_CE = 2.5V)
• Collector-Emitter Saturation Voltage (V_CE(sat)): < 1>C = 150mA, I_B = 15mA)
• Base-Emitter Saturation Voltage (V_BE(sat)): < 1>C = 150mA, I_B = 15mA)
• Transition Frequency (f_T): 100 MHz (Minimum at I_C = 50mA, V_CE = 10V, f = 100MHz)
• Output Capacitance (C_ob): Maximum 15pF (at V_CB = 10V, I_E = 0, f = 1.0MHz)
• Total Power Dissipation (P_D): 1.0W (at T_amb = 25°C in free air) / Up to 5.0W (at T_case = 25°C with heatsink)
• Operating Junction & Storage Temperature: -65°C to +200°C
• Package / Case: TO-39 (3-Lead Metal Can: Pin 1: Emitter, Pin 2: Base, Pin 3: Collector connected to Case)

Features

• Rugged TO-39 Metal Can Package: Provides superior mechanical protection, hermetic isolation, and enhanced thermal dissipation compared to plastic packages.
• Medium Current Capability: Drives continuous loads up to 700mA, easily bridging the gap between low-power small-signal transistors and large power devices.
• Wide Gain Bandwidth (100MHz): High transition frequency makes it suitable for high-frequency signal processing, video amplifiers, and fast pulse circuits.
• High Junction Temperature Headroom: Capable of withstanding operating temperatures up to +200°C for demanding industrial and test environments.
• Proven Linearity & Low Capacitance: Low output capacitance (15pF max) ensures clean signal fidelity in linear audio driver stages.

Common Applications

• Audio Preamplifier & Driver Stages: Intermediate driver amplification in discrete Class-AB and vintage audio amplifier systems.
• Relay, Solenoid & Lamp Driving: Switching medium-power electromechanical loads and indicators from low-voltage logic controllers.
• Linear Voltage Regulators: Series pass-transistor and driver stage in discrete linear bench power supplies.
• RF & VHF Oscillators / Drivers: Small-signal RF amplification and oscillator circuits in communication receivers and transmitters.
• General-Purpose Breadboarding & Prototyping: Reliable, through-hole metal-can transistor for educational kits and maker projects.

Usage Tips

• Pin Identification & Case Grounding: The TO-39 package features an index tab pointing directly to the Emitter (Pin 1); the Base (Pin 2) is in the center, and the Collector (Pin 3) is electrically bonded to the metal housing. Ensure the outer metal can does not make unintended electrical contact with adjacent grounded chassis parts.
• Base Resistor Calculation: Always install an appropriate base current-limiting resistor (R_B) between the driving GPIO/signal and the Base to prevent over-current; use a 10:1 saturation ratio (I_B ≈ I_C / 10) for reliable switching.
• Base Pull-Down Resistor: Connect a 10kΩ resistor between the Base and Emitter (GND) to keep the transistor fully cut off when the input signal is floating or during microcontroller bootup.
• Heatsink Attachment: When dissipating power over 1W or operating at high ambient temperatures, fit a clip-on TO-39 star heatsink to maintain safe junction temperatures.
• Inductive Clamping: When driving inductive loads (coils, relays, small DC motors), connect a reverse-biased flyback diode across the load to protect the collector junction against back-EMF spikes.

Datasheet