2N3772

2N3772 NPN Power Transistor Technical Summary

Overview

The 2N3772 is a silicon epitaxial-base NPN power transistor designed for high-power amplification and switching applications. Housed in a rugged TO-3 metal package, this component offers excellent thermal and electrical performance in demanding environments. As part of the 2N377x series (including the 2N3771), it provides robust current handling capabilities with a focus on reliability under sustained high-load conditions.

Developed using epitaxial growth techniques, the transistor achieves optimal charge carrier mobility while maintaining structural integrity at elevated temperatures. The TO-3 package features a threaded stud for secure mounting to heatsinks, making it suitable for applications requiring substantial power dissipation.

Key Features

• High Current Capacity: 30A continuous collector current rating
• Voltage Resilience: 140V collector-emitter breakdown voltage (V_CEO)
• Power Handling: 150W total power dissipation at 25°C case temperature
• Robust Construction: Epitaxial-base silicon construction for thermal stability
• Low Saturation Voltage: V_CE(sat) of 1.5V (typical) at I_C = 15A
• TO-3 Package: Industry-standard metal can package with isolated mounting
• Wide Temperature Range: Operational from -65°C to +200°C

Applications

The 2N3772 finds use in both commercial and industrial power electronics systems where reliability under high stress conditions is paramount:

• Power Amplifiers: Linear amplification stages in audio and RF systems
• Switching Regulators: High-current DC-DC conversion circuits
• Motor Control: H-bridge configurations for industrial motors
• Power Supplies: Series pass elements in regulated power supplies
• Inverters/UPS: Power conversion stages in uninterruptible power systems
• Industrial Controls: Solenoid/relay drivers and contactor circuits

Electrical Characteristics (T_A = 25°C unless specified)

Absolute Maximum Ratings

• Collector-Emitter Voltage (V_CEO): 140V
• Collector-Base Voltage (V_CBO): 160V
• Emitter-Base Voltage (V_EBO): 7V
• Collector Current (I_C): 30A continuous
• Base Current (I_B): 10A
• Total Power Dissipation (P_D): 150W @ T_C ≤ 25°C
• Operating Junction Temperature Range: -65°C to +200°C
• Storage Temperature Range: -65°C to +200°C

Thermal Characteristics

• Thermal Resistance, Junction-to-Case (R_θJC): 0.7°C/W
• Thermal Resistance, Junction-to-Ambient (R_θJA): 35°C/W (mounted on infinite heatsink)

DC Current Gain Characteristics

• h_FE (I_C = 15A, V_CE = 4V): 15-60
• h_FE (I_C = 30A, V_CE = 4V): 10-40

Switching Characteristics

• Turn-On Time (t_on): 1.0μs (typical)
• Turn-Off Time (t_off): 3.5μs (typical)
• Collector Capacitance (C_ob): 300pF @ V_CB = 10V

Package Information (TO-3 Metal Can)

Mechanical Specifications

• Package Type: JEDEC TO-3 (TO-204AA)
• Mounting Style: Threaded stud (10-32 UNF) with insulating shoulder washer
• Material: Steel body with nickel plating
• Terminals: Gold-plated leads for reliable connections
• Weight: 23g (approximate)

Dimensions

• Overall Height: 19.05mm (0.750in)
• Base Diameter: 27.94mm (1.100in)
• Lead Length: 19.05mm (0.750in) minimum
• Lead Diameter: 1.02mm (0.040in)

Pin Configuration

• Pin 1 (Base): Center lead when viewing package bottom
• Pin 2 (Collector): Package case (electrically connected to mounting stud)
• Pin 3 (Emitter): Offset lead when viewing package bottom

Reliability Data

The 2N3772 demonstrates exceptional reliability when operated within specified parameters:

• MTBF (Mean Time Between Failures): >1,000,000 hours at 50% rated load
• ESD Protection: Withstands 2kV human body model discharges
• Moisture Resistance: Passes MIL-STD-202 Method 106 moisture resistance testing

Handling & Mounting Considerations

Proper installation is critical for optimal performance:

• Always use thermal compound between package base and heatsink
• Recommended torque for mounting nut: 8-10 in-lbs
• Maintain minimum 0.005" clearance between transistor base and heatsink
• Use insulating hardware when electrical isolation is required
• Avoid bending leads more than 0.125" from package body

Derating Guidelines

For operation above 25°C case temperature:

• Power dissipation must be reduced by 1.2W/°C above 25°C
• Maximum collector current decreases linearly above 25°C case temperature
• Derate V_CEO by 0.5V/°C above 25°C

Alternative Components

When the 2N3772 is unavailable, consider these substitutes with similar characteristics:

• 2N3771 (lower current rating but same voltage characteristics)
• 2N3773 (higher voltage variant)
• MJ15003 (modern equivalent with improved gain characteristics)
• MJ15024 (complementary PNP type for push-pull configurations)