MJ2955 - 15A 60V PNP Power Transistor | TO-3 | onsemi
料号： MJ2955 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.18 | $21.80 |
| 100 | $1.85 | $185.00 |
| 500 | $1.62 | $810.00 |
| 1,000 | $1.4 | $1,400.00 |
MJ2955 概述
A bipolar junction transistor (BJT) is a three-terminal semiconductor device that uses a small base current to control a much larger collector current, achieving current gain typically expressed as hFE. Power BJTs like the MJ2955 are optimized for high-current and high-voltage switching or linear amplification, where their low saturation voltage and robust SOA are advantageous. Within the power semiconductor hierarchy, the MJ2955 sits as a PNP power BJT, complementary to NPN power BJTs such as the 2N3055, and is typically deployed where polarity-symmetric drive or negative-rail regulation is required.
Key features include 60 V VCBO, 7 A continuous base current, an epitaxial-base planar die for tight parametric distribution, and hermetic TO-3 metal packaging rated for chassis-mount heatsink attachment. The TO-3 case provides low thermal resistance, high mechanical ruggedness, and a bolt-down mounting style that suits industrial, audio, and military-grade applications where long-term reliability is critical.
The MJ2955 uses an epitaxial-base mesa structure delivering typical DC current gain (hFE) of 20 to 70 at IC = 4 A, supporting both linear amplification and saturated switching. Its collector-emitter saturation voltage of approximately 1.1 V at rated current makes it efficient in linear regulators and audio output stages, while the 4 MHz transition frequency supports moderate-bandwidth amplifier designs.
Typical applications include linear power supplies and series regulators, hi-fi audio amplifier output stages, DC motor drivers, inverter and converter stages, and general-purpose high-power switching. The MJ2955's complementary nature to the 2N3055 makes it a standard choice for push-pull Class AB amplifier output pairs.
When designing with this device, always use a proper mica or silicone-insulated heatsink mount and ensure the collector case potential is acceptable for your circuit topology, since the TO-3 case is electrically tied to the collector. Keep base drive current within the rated 7 A limit and observe the SOAR curve at high VCE.
This page synthesizes distributor pricing, drop-in TO-3 alternatives, and practical heatsink design notes not consolidated on the manufacturer datasheet, giving procurement and design engineers a single reference for sourcing and substituting the MJ2955.
直接替换替代料： MJ2955 ——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：
MJ2955G
✅ 直接替换📋 参考替代料（不在目录中）
2N2955
✅ 直接替换📋 参考替代料（不在目录中）
MJ15016
✅ 直接替换📋 参考替代料（不在目录中）
2N5880
✅ 直接替换📋 参考替代料（不在目录中）
2N6248
✅ 直接替换📋 参考替代料（不在目录中）
MJ2955 最大额定值与电气特性
| 晶体管类型 | PNP |
| Polarity | PNP (complement of 2N3055) |
| 集电极-发射极电压（Vceo） | 60 V |
| 集电极-基极电压（Vcbo） | 60 V |
| 发射极-基极电压（Vebo） | 7 V |
| Continuous Collector Current (IC) | 15 A |
| Continuous Base Current (IB) | 7 A |
| Power Dissipation (PD) | 115 W at 25 °C case |
| Junction-to-Case Thermal Resistance (θJC) | 1.52 °C/W |
| DC Current Gain (hFE) | 20 to 70 (at IC = 4 A, VCE = 4 V) |
| 集电极-发射极饱和电压（Vce(sat)） | 1.1 V typical (at IC = 15 A) |
| 过渡频率（ft） | 4 MHz |
| 工作结温 | -65 °C to +200 °C |
| 封装 | TO-3 (TO-204-3) metal case |
| 安装类型 | Chassis / Through-hole bolt-down |
| RoHS 状态 | Compliant |
MJ2955 引脚配置
| 引脚 1 | Base — Base control terminal |
| 引脚 2 | Emitter — Emitter terminal |
| 引脚 3 | Collector — Collector - internally bonded to metal case |
安全工作区 (DC, TJ <= 200 °C)
典型应用
MJ2955 适用于 6 应用s: Linear Power Supply Series Regulator, Hi-Fi Audio Amplifier Output Stage, DC Motor Driver / H-Bridge, Battery Charger Current Source, Power Inverter / Switch-Mode Output Stage, Automotive Voltage Regulator / Alternator Control.
Linear Power Supply Series Regulator
The MJ2955 is a workhorse for linear series-pass regulators where its 60 V VCEO and 15 A continuous collector current deliver ample headroom for 5 V to 48 V rails. Its low 1.1 V VCE(sat) and 1.52 °C/W θJC reduce waste heat compared to Darlington alternatives. Designers bias the base from a TL431 reference through a driver transistor, with the MJ2955 dissipating up to 115 W on a bolted heatsink. The hermetic TO-3 case provides decades of proven reliability in industrial and lab-grade supplies.
推荐
Hi-Fi Audio Amplifier Output Stage
The MJ2955 is the classic PNP half of a complementary Class AB audio output stage, paired with the 2N3055 NPN on the same TO-3 heatsink. Its 15 A peak collector current and 115 W dissipation comfortably deliver 50-100 W into 8 Ω. The epitaxial-base process yields matched hFE between complementary pairs, minimizing crossover distortion. The TO-3 metal case is bolted to a finned heatsink, providing thermal mass that absorbs music transients without thermal runaway, making it a staple in vintage and modern hi-fi amplifiers.
推荐
DC Motor Driver / H-Bridge
The MJ2955 handles the low-side PNP switches in an H-bridge driving DC motors up to 15 A continuous. Its 60 V VCEO tolerates back-EMF spikes from 24 V and 36 V brushed motors, while its 1.52 °C/W θJC sustains heavy stall-current loads with proper heatsinking. Designers typically drive the base via a logic-level MOSFET predriver and add flyback diodes across each transistor. The TO-3 package is rugged against the mechanical vibration common in motor-control enclosures.
推荐
Battery Charger Current Source
The MJ2955 is ideal for constant-current battery charging circuits requiring high current capacity up to 15 A for lead-acid and lithium battery packs. Its PNP common-emitter configuration naturally regulates current when the base is held at a fixed voltage, drawing 15 A continuously at 60 V max collector voltage with 1.1 V VCE(sat) minimizing wasted power. The TO-3 chassis-mount case bolts directly to the charger enclosure, providing the 1.52 °C/W thermal path needed for sustained float-charge operation.
推荐
Power Inverter / Switch-Mode Output Stage
The MJ2955 finds a role in low-frequency power inverter output stages driving 50/60 Hz transformers from a battery bank. Its 15 A continuous and 60 V rating handle 12 V and 24 V battery systems comfortably, while its hermetic TO-3 case tolerates the thermal cycling of repeated full-load pulses. Designers use the MJ2955 in complementary pairs with the 2N3055 in a push-pull topology, switched at line frequency. The high 115 W dissipation supports multi-hundred-W inverter modules.
推荐
Automotive Voltage Regulator / Alternator Control
The MJ2955's 60 V VCEO and 15 A current rating make it well suited to automotive voltage regulator and alternator field-control circuits where load-dump transients up to 60 V are routine. Its hermetic TO-3 case withstands under-hood thermal and vibration stress while delivering 115 W continuous dissipation. Designers wire the MJ2955 as a series-pass element or Darlington predriver in classic electromechanical regulator replacements. Pin compatibility with the 2N3055 enables simple NPN/PNP symmetric regulator designs.
推荐
推荐产品汇总
工程参考数据： MJ2955 ——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 | MJ2955G | 2N2955 | MJ15016 | 2N5880 | 2N6248 | MJ2955 (ST) |
|---|---|---|---|---|---|---|---|
| Brand | onsemi | onsemi | onsemi | onsemi | onsemi | onsemi | STMicroelectronics |
| Package | TO-3 (TO-204-3) | TO-3 (TO-204-3) - same | TO-3 (TO-204-3) - same | TO-3 (TO-204-3) - same | TO-3 (TO-204-3) - same | TO-3 (TO-204-3) - same | TO-3 (TO-204-3) - same |
| VCEO (V) | 60 | 60 | 60 | 120 | 60 | 110 | 60 |
| Continuous IC (A) | 15 | 15 | 15 | 15 | 25 | 13 | 15 |
| Power Dissipation (W) | 115 | 115 | 115 | 150 | 200 | 125 | 115 |
| θJC (°C/W) | 1.52 | 1.52 | 1.52 | 1.0 | 0.875 | 1.4 | 1.52 |
| Polarity | PNP | PNP | PNP | PNP | PNP | PNP | PNP |
| RoHS / Lead-free | Non-RoHS (SnPb) | RoHS (Pb-free) | Non-RoHS | RoHS (Pb-free) | RoHS (Pb-free) | Non-RoHS | RoHS (Pb-free) |
关键差异点
- Industry-standard TO-3 metal-case PNP complement of 2N3055 （对比 2N3055)
- Lowest-cost RoHS drop-in option available as MJ2955G （对比 MJ2955 (SnPb))
- Higher-current TO-3 upgrade path within onsemi family （对比 2N5880)
设计说明
Estimated: at IC=10 A and VCE=4 V (linear regulator), the MJ2955 dissipates roughly 40 W. With θJC = 1.52 °C/W and a 25 °C case temperature, the junction rises to about 86 °C. Always mount the TO-3 case to a heatsink sized for the maximum continuous dissipation; a bare TO-3 at 25 °C ambient can only handle ~3 W. Use thermal compound and a torque wrench to 0.6-0.8 N·m on the mounting screws to avoid cracking the case.
The TO-3 case is electrically tied to the collector. For chassis-mount applications where the case must float, isolate the transistor with a mica or silicone washer and a nylon shoulder washer on the mounting screw. For grounded-case designs, mount the TO-3 directly to a grounded heatsink for lowest thermal resistance. Keep base and emitter leads short to minimize switching transients in audio applications.
Never substitute the 2N3055 (NPN) for the MJ2955 (PNP) - they are complementary, not interchangeable. Exceeding the 60 V VCEO with inductive kickback (relays, motors) will destroy the part; always clamp with flyback diodes. The 7 A base current rating is absolute - exceeding it destroys the bond wires. Keep VCE(sat) derating in mind: 1.1 V at 15 A means 16.5 W wasted even in saturation.
合规信息
Standard MJ2955 uses SnPb finish (non-RoHS); choose MJ2955G (Pb-free) for RoHS-compliant end products. Not AEC-Q100 qualified - this is a chassis-mount part for industrial/consumer, not automotive-grade.
