BD139 TO-126 Transistor – KSH 10 at HIMASTORES Mombasa – best electronics in Kenya
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BD139 TO-126 Transistor

SKU: HMJ836 Category: Transistors
KSH 10.00
In Stock

Product Description

BD139 TO-126 Transistor (NPN)

1.5A NPN Medium Power Transistor for Audio and Switching Applications

The BD139 is a mediumpower NPN bipolar junction transistor (BJT) housed in a TO126 (SOT32) plastic package[citation:1][citation:7]. It is designed for audio amplifiers and drivers utilizing complementary or quasicomplementary circuits and is the NPN complement to the PNP transistor BD140[citation:1][citation:5][citation:11].

Device Type: NPN Bipolar Junction Transistor (BJT)
Package: TO-126[citation:1][citation:5]
Maximum Collector Current (IC): 1.5A (DC); 3A pulse[citation:1][citation:7]
PNP Complement: BD140[citation:5][citation:11]
Ensure correct pin identification: Pin 1 is the Emitter, Pin 2 is the Collector, and Pin 3 is the Base[citation:2][citation:7][citation:8]. The collector is electrically connected to the metal mounting tab[citation:5].
Do not exceed the maximum ratings to prevent permanent damage.

Key Technical Specifications

ParameterValueNotes
:-:-:-
Collector-Emitter Voltage (VCEO)80VMaximum continuous voltage[citation:1][citation:7]
Collector-Base Voltage (VCBO)80V[citation:2][citation:4]
Emitter-Base Voltage (VEBO)5V[citation:2][citation:4]
Collector Current (IC)1.5AContinuous current rating[citation:1][citation:7]
Power Dissipation (Ptot)1.25W (without heatsink) / 12.5W (with heatsink)[citation:1][citation:6][citation:9]With proper heatsinking
DC Current Gain (hFE)40 - 250Depends on variant and conditions[citation:4][citation:7][citation:11]
Transition Frequency (fT)190 MHzTypical value[citation:4][citation:5][citation:11]
Operating Junction Temperature-55°C to +150°C[citation:4][citation:5][citation:7]

= Key Features =

Complementary NPN Design - Designed as a complementary transistor to the BD140 (PNP)[citation:5][citation:11]

High Current Capability 1.5A continuous collector current for mediumpower applications[citation:1][citation:7]

Low Saturation Voltage - 0.5V max at IC = 500mA ensures low conduction losses[citation:1][citation:9]

Versatile Performance - 190 MHz transition frequency for suitability in audio and driver stages[citation:4][citation:5]

= Applications =

  • Audio amplifiers and drivers[citation:1][citation:7]
  • General-purpose power applications[citation:1][citation:10]
  • Power management circuits[citation:1]
  • Industrial control[citation:1]
  • Load driver circuits[citation:11]
Reliable Performance - Designed for audio amplifiers and drivers[citation:1]
Widely Available Standard TO126 package with well-documented specifications

√ Ready to use A standard and welldocumented power transistor

√ Medium power capability - Suitable for a wide range of applications

√ Multiple hFE ranks - Available in 6, 10, and 16 classifications with different gain ranges[citation:7]

Package Includes

  1. 1x BD139 NPN Transistor (TO-126 Package)
For reliable operation, ensure adequate heatsinking when dissipating significant power (above 1.25W)
This device is part of a complementary family with BD140. The SMD equivalent is the BCP56 (SOT-223 package)[citation:11]
The BD13916 variant offers a higher hFE range of 100250[citation:7]
For precise pin identification, the standard TO-126 configuration is Emitter (1), Collector (2), Base (3)[citation:2][citation:7][citation:8].

Avoid exceeding the maximum voltage ratings the collector-emitter voltage (VCEO) of 80V is critical

-Avoid exceeding the maximum junction temperature of 150°C

-Avoid using this transistor as a direct replacement without confirming the pinout and specifications