MJE2955T — -60V -10A Power PNP BJT (Plastic TO-220 2N2955 Equivalent)

Overview

The MJE2955T is a -60V -10A silicon power PNP bipolar junction transistor manufactured by onsemi and STMicroelectronics. Housed in a through-hole TO-220AB plastic package, it was engineered as the direct plastic-package equivalent of the historic 2N2955 / MJ2955 metal TO-3 diamond-case power transistor.

Providing a collector-emitter breakdown voltage ( $V_{CEO}$ ) of $-60\text{V}$ , a high continuous collector current rating of $-10.0\text{A}$ , and a massive power dissipation capability of $75\text{ Watts}$ at $T_C = 25^\circ\text{C}$ ( $\theta_{JC} = 1.67^\circ\text{C/W}$ ), the MJE2955T serves as the official PNP complement to the MJE3055T. Together, the MJE3055T/MJE2955T pair is the industry benchmark for high-power complementary Class AB audio amplifiers (40W–100W), dual-polarity laboratory power supply series-pass stages, and high-current DC motor speed controllers.

Quick reference


Transistor Type	High-Power Silicon PNP Power BJT
Package	TO-220AB (3-pin through-hole)
Collector-Emitter Breakdown ( $V_{CEO}$ )	$-60\text{ V}$ max
Collector-Base Breakdown ( $V_{CBO}$ )	$-70\text{ V}$ max
Continuous Collector Current ( $I_C$ )	$-10.0\text{ A}$ max
Base Current ( $I_B$ )	$-6.0\text{ A}$ max
DC Current Gain ( $h_{FE}$ )	$20$ to $100$ ( $I_C = -4.0\text{A}, V_{CE} = -4.0\text{V}$ ) / $\ge 5$ at $-10\text{A}$
Collector Saturation ( $V_{CE(sat)}$ )	$-1.1\text{ V}$ max ( $I_C = -4.0\text{A}, I_B = -400\text{mA}$ ) / $-3.0\text{V}$ at $-10\text{A}$
Total Power Dissipation ( $P_D$ )	$75\text{ Watts}$ ( $T_C = 25^\circ\text{C}$ with heatsink) / $1.75\text{ W}$ free air
Transition Frequency ( $f_T$ )	$2.0\text{ MHz}$ min
Thermal Resistance ( $\theta_{JC}$ )	$1.67^\circ\text{C/W}$ (Junction-to-Case)
Complementary NPN Pair	MJE3055T (60V 10A NPN)

Pinout (TO-220AB Package - B-C-E Standard)

Looking at the front labeled face with leads pointing downward:

text

        ┌──────────────┐
        │  O  [Metal]  │ ── Tab is internally connected to Pin 2 (Collector)
        ├──────────────┤
        │   MJE2955T   │
        └─┬────┬────┬──┘
          1    2    3
          B    C    E

Pin	Name	Type	Description
1	`BASE (B)`	Base Input	Base control input (Driven with base current via driver transistor)
2 (Tab)	`COLLECTOR (C)`	Power Collector	Collector terminal (Internally connected to metal mounting tab)
3	`EMITTER (E)`	Power Emitter	Emitter terminal (Connect to positive supply rail or output resistor)

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Collector-Emitter Breakdown	$V_{(BR)CEO}$	-60	—	—	V	$I_C = -30\text{mA}, I_B = 0$
Collector-Base Breakdown	$V_{(BR)CBO}$	-70	—	—	V	$I_C = -1.0\text{mA}, I_E = 0$
Emitter-Base Breakdown	$V_{(BR)EBO}$	-5.0	—	—	V	$I_E = -1.0\text{mA}, I_C = 0$
Collector Cutoff Current	$I_{CEO}$	—	—	-700	µA	$V_{CE} = -30\text{V}, I_B = 0$
DC Current Gain ( $h_{FE}$ )	$h_{FE}$	20	—	100	—	$I_C = -4.0\text{A}, V_{CE} = -4.0\text{V}$
DC Current Gain ( $h_{FE}$ )	$h_{FE}$	5	—	—	—	$I_C = -10.0\text{A}, V_{CE} = -4.0\text{V}$
Collector Saturation Voltage	$V_{CE(sat)}$	—	—	-1.1	V	$I_C = -4.0\text{A}, I_B = -400\text{mA}$
Collector Saturation Voltage	$V_{CE(sat)}$	—	—	-3.0	V	$I_C = -10.0\text{A}, I_B = -3.3\text{A}$
Base-Emitter On Voltage	$V_{BE(on)}$	—	—	-1.8	V	$I_C = -4.0\text{A}, V_{CE} = -4.0\text{V}$

Typical Application: 60W Hi-Fi Complementary Audio Power Amplifier Output Stage

text

                            +35V Positive DC Power Rail
                                         │
                                  [Pin 2: COLLECTOR]
                                     MJE3055T (NPN)
  From Driver (BD139) ───────────►[Pin 1: BASE]
                                  [Pin 3: EMITTER]
                                         │
                                         ├───[ 0.22Ω 5W Resistor ]───┐
                                         │                           ├────► Audio Output (to 8Ω Speaker)
                                         ├───[ 0.22Ω 5W Resistor ]───┘
                                  [Pin 3: EMITTER]
  From Driver (BD140) ───────────►[Pin 1: BASE]
                                     MJE2955T (PNP)
                                  [Pin 2: COLLECTOR]
                                         │
                            -35V Negative DC Power Rail

Comparison: MJE2955T vs MJ2955 vs TIP42C

Parameter	MJE2955T	MJ2955	TIP42C
Package	TO-220AB (Plastic)	TO-3 (Metal Diamond)	TO-220AB (Plastic)
$V_{CEO}$ Voltage	$-60\text{ V}$	$-60\text{ V}$	$-100\text{ V}$
Max Current ( $I_C$ )	$-10\text{ A}$	$-15\text{ A}$	$-6.0\text{ A}$
Power Dissipation ( $P_D$ )	$75\text{ W}$	$115\text{ W}$	$65\text{ W}$
Complementary NPN	MJE3055T	2N3055	TIP41C

Common mistakes

Driving base directly without a pre-driver transistor: At high currents ( $I_C = -4\text{A}$ ), the base requires $I_B \approx -400\text{mA}$ . Always use a pre-driver transistor (such as the BD140 or TIP32C) to supply base current.
Operating without a heavy heatsink: When delivering continuous audio or linear power, thermal dissipation can exceed $30\text{W} \dots 50\text{W}$ . Always use a large heatsink with thermal paste and insulating mica/silicone mounting kits.

Notes

Suffix Guide: MJE2955T is standard TO-220; MJE2955TG denotes lead-free RoHS compliance; MJE3055T is the complementary NPN partner.