MJE3055 - NPN BJT 60V 10A 75W Power Transistor | STMicroelectronics
料号： MJE3055 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $0.55 | $0.55 |
| 10 | $0.48 | $4.80 |
| 100 | $0.39 | $39.00 |
| 500 | $0.31 | $155.00 |
| 1,000 | $0.25 | $250.00 |
MJE3055 概述
A bipolar junction transistor is a three-terminal current-controlled semiconductor device in which a small base current controls a much larger collector current. Power BJTs like the MJE3055 sit at the top of the discrete-transistor hierarchy (transistor -> power transistor -> BJT -> NPN power BJT) and remain widely used in linear power stages, audio output stages, and medium-voltage switching circuits where MOSFET drive complexity is unnecessary.
Key features include DC current gain specified up to 10A, hFE of 20 to 100 at IC = 4A, and a minimum transition frequency fT of 2.0 MHz at IC = 500 mAdc, per the original Motorola datasheet. The TO-220 package with metal tab allows direct mounting to a heatsink, and the device is offered by STMicroelectronics, onsemi (MJE3055TG), and other manufacturers with near-identical specifications.
The epitaxial-base construction provides robust safe-operating-area behavior for resistive and inductive loads. Because fT is 2 MHz, the device suits low- and medium-frequency power stages rather than high-speed switching; rise and fall times are dominated by storage charge, so anti-saturation Baker clamps or negative base drive improve switching performance in converter designs.
Typical applications include class-AB audio amplifier output pairs with the complementary MJE2955 PNP, relay and solenoid drivers, linear regulators as pass elements, and DC motor speed-control bridges. The 10A rating with adequate heatsinking covers most bench-supply and actuator loads.
Design tip: the TO-220 tab is connected to the collector, so insulate the heatsink or use an isolated package variant when the collector potential is exposed.
This page adds value beyond the datasheet with cross-manufacturer drop-in alternatives, parameter comparison tables, drop-in replacement guidance, and practical thermal design notes in one place.
直接替换替代料： MJE3055 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
MJE3055T
✅ 直接替换📋 参考替代料（不在目录中）
MJE3055TG
✅ 直接替换📋 参考替代料（不在目录中）
MJE3055-BP
✅ 直接替换📋 参考替代料（不在目录中）
MJE3055K
✅ 直接替换📋 参考替代料（不在目录中）
MJE3055T-BP
✅ 直接替换📋 参考替代料（不在目录中）
MJE3055 最大额定值与电气特性
| Polarity | NPN |
| Collector-Emitter Breakdown Voltage (VBRCEO) | 60 V (min) |
| Continuous Collector Current (IC) | 10 A |
| Power Dissipation (PD) | 75 W (TC = 25C) |
| DC Current Gain (hFE) | 20 to 100 @ IC = 4 A |
| 过渡频率（ft） | 2.0 MHz (min) @ IC = 500 mAdc |
| DC Current Gain Specified To | 10 A |
| Complementary PNP Type | MJE2955 |
| 封装 | TO-220 (through hole) |
| 安装类型 | Through Hole |
| Technology | Silicon epitaxial-base |
| Configuration | Single transistor |
| Application Class | General-purpose amplifier and switching |
MJE3055 引脚配置
| 引脚 1 | Base — Base control terminal - drive with base current through a current-limiting resistor |
| 引脚 2 | Collector — Collector current terminal; internally connected to the metal mounting tab |
| 引脚 3 | Emitter — Emitter terminal; reference for base drive in common-emitter configurations |
MJE3055 DC 安全工作区 (TC = 25C)
典型应用
MJE3055 适用于 6 应用s: Class-AB Audio Amplifier Output Stage, Relay and Solenoid Driving, Linear Power Supply Pass Element, DC Motor Speed Control (H-Bridge / PWM), General-Purpose Medium-Power Switching, Robotics and Hobby Power Stages.
Class-AB Audio Amplifier Output Stage
The MJE3055 paired with its complementary MJE2955 PNP forms a classic push-pull class-AB output pair. Its hFE of 20-100 at 4A lets driver stages supply adequate base current at output peaks, while the 2.0 MHz fT provides ample bandwidth beyond the 20 kHz audio limit, keeping crossover distortion manageable with proper bias diodes. In a typical amplifier, each device handles half the output waveform with 0.1-0.47 ohm emitter resistors for current sharing and thermal stability. Because the 75W dissipation rating applies at 25C case temperature, a substantial heatsink with thermal paste is required for continuous high output power. The MJE3055 remains a favorite for DIY and replacement amplifier builds due to its low cost and wide availability across multiple manufacturers.
推荐
Relay and Solenoid Driving
The MJE3055 drives relays, solenoids, and valves directly from microcontroller logic through a base resistor. With a 10A collector rating and 60V VBRCEO, it handles large inductive loads that would overwhelm small-signal BJTs, and its rugged bipolar construction tolerates the surge currents characteristic of solenoid inrush. A typical circuit uses a 1k base resistor from a 5V logic line, a flyback diode across the coil to clamp inductive kick, and a pull-down to keep the device off during startup. Because the TO-220 tab is at collector potential and load coils often sit at supply voltage, insulate the tab or mount the heatsink carefully. Compared with a logic-level MOSFET, the MJE3055 costs less and tolerates gate-less drive, at the price of continuous base current draw.
推荐
Linear Power Supply Pass Element
As a series pass transistor in a linear regulator, the MJE3055 provides gain and current capacity for bench supplies and post-regulators. Operating in the active region, its collector current of up to 10A with hFE specified to 10A means an error-amplifier stage can control a 3A-5A output using only tens to hundreds of milliamps of drive. The 60V rating supports 24V and 48V bus-derived supplies with margin, and the epitaxial construction holds up against output-short transients when current limiting is applied. Estimated: at 5A output with 5V headroom the device dissipates 25W, requiring a heatsink around 1 C/W to keep the case near 50C. Fold-back current limiting is recommended to limit SOA stress during short-circuit events.
推荐
DC Motor Speed Control (H-Bridge / PWM)
The MJE3055 works in low-frequency PWM motor drivers and H-bridge legs, typically paired with the MJE2955 PNP for bidirectional control. Its high gain at 4A reduces driver-stage loading, and the 60V breakdown absorbs inductive spikes beyond the rail when clamped by freewheeling diodes. Because fT is 2 MHz and power BJTs suffer storage-time delay, PWM frequencies should stay in the low kilohertz range to limit switching losses; adding a small speed-up capacitor or Baker clamp across the base resistor improves edge sharpness. Estimated: at 5A load with about 1V saturation plus 1.5V average switching overhead, each device dissipates roughly 12W at 50% duty, mandating heatsinking. Darlington pre-drivers (e.g., TIP122-family) raise input impedance when MCU drive current is limited.
推荐
General-Purpose Medium-Power Switching
For heaters, lamps, fans, solenoids, and RC car actuators switching tens of watts at low frequency, the MJE3055 offers a cheap, forgiving solution. Its specified gain up to 10A and 60V rating cover most 12V and 24V loads, and the industry-standard TO-220 footprint means replacements are available from STMicroelectronics, onsemi, and MCC. A practical design gives the base 1/10th to 1/20th of collector current to ensure hard saturation, accepting slightly higher drive in exchange for low VCE(sat) and low conduction loss. Estimated: with 500 mA base drive at 5A load, forced beta of 10 keeps the device firmly saturated. Remember the tab connects to the collector - in low-side switches that places switching voltage on the heatsink, so use insulating hardware.
推荐
Robotics and Hobby Power Stages
Hobby robotics, RC vehicles, and maker projects use MJE3055/MJE2955 pairs for drive stages, battery-powered speed controllers, and dump loads because they are inexpensive, through-hole solderable, and stocked worldwide. The 10A continuous rating comfortably drives gearmotor loads, and the TO-220 package bolts directly to folded-aluminum heatsinks common in hobby builds. Its forgiving bipolar drive means a simple transistor-and-resistor interface from an Arduino or microcontroller works without MOSFET gate-driver considerations. For overcurrent events such as motor stall, the bipolar device's SOA behavior combined with a fuse or polyfuse gives robust protection. Builders should budget base-drive current from a driver transistor and keep PWM below a few kHz, consistent with the part's 2 MHz fT and storage-time behavior.
推荐
推荐产品汇总
工程参考数据： MJE3055 ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | MJE3055T | MJE3055TG | MJE3055-BP | MJE3055K |
|---|---|---|---|---|---|
| Package | TO-220 | TO-220 - same | TO-220 - same | TO-220 - same | TO-220 - same |
| Brand | STMicroelectronics | STMicroelectronics | onsemi | Micro Commercial Components (MCC) | Inchange Semiconductor |
| VBRCEO | 60 V | 60 V | 60 V | 60 V | 60 V (min) |
| Collector Current | 10 A | 10 A | 10 A | 10 A | 10 A |
| Power Dissipation | 75 W (TC = 25C) | 75 W | 75 W | 75 W | 75 W |
| Pinout (B-E-C) | 1=B, 2=C, 3=E | 1=B, 2=C, 3=E - same | 1=B, 2=C, 3=E - same | 1=B, 2=C, 3=E - same | 1=B, 2=C, 3=E - same |
关键差异点
- Gain specified up to full 10A rating （对比 MJE3055-BP (MCC))
- Pb-free G-suffix variant available （对比 MJE3055T)
- Industry-standard complementary pairing （对比 MJE3055K (Inchange))
设计说明
The 75W power dissipation rating applies at a 25C case temperature, which is only achievable on an effectively infinite heatsink. Estimated: with a typical 3 C/W heatsink and 1 C/W junction-to-case resistance, sustained dissipation should be kept below about 30W to hold the junction near its limit. Always use thermal grease or a phase-change pad, torque the TO-220 screw to specification, and derate for ambient temperature. For linear and audio applications, measure case temperature at worst-case output power during design validation.
Keep base and emitter traces short and low-inductance, and place the base drive resistor close to pin 1. Because the metal tab is the collector, do not route other nets under the mounting hole area unless the tab is insulated; a mica or silicone pad plus shoulder washer electrically isolates the collector from the heatsink at a small thermal resistance penalty (typically adding a fraction of a C/W). For multi-device output stages, thermally couple devices to the same heatsink and use emitter resistors (0.1-0.47 ohm) for current sharing and thermal runaway protection.
The most common failure mode is driving the base with insufficient current: at 10A collector current the hFE can be as low as 20, requiring up to 500 mA of base drive for hard saturation in switching duty. A microcontroller pin cannot supply this - use a driver transistor or Darlington stage. Also avoid fast PWM: with fT of only 2 MHz and significant storage time, high-frequency switching causes excessive dissipation. Finally, always clamp inductive loads with a flyback diode; bipolar devices without avalanche rating are destroyed by unclamped inductive kick.
合规信息
Compliance depends on manufacturer suffix: STMicroelectronics MJE3055T and onsemi MJE3055TG (Pb-free G suffix) are marketed as RoHS/lead-free parts, but compliance for the generic MJE3055 ordering code was not stated in the retrieved data and is marked unknown.
