Fast & free stop-desk delivery from 4000 DA | Flexible payment | Technical support for your builds
BinaryTech DZ

Transistors and DIACs

368 results

Bipolar transistors, MOSFETs, IGBTs, JFETs and DIACs in through-hole and SMD packages, for switching, amplifying or driving a motor, an LED or a power supply.

Child categories

DIAC

1 products

JFET Transistors

2 products

MOSFET Transistors

144 products

Bipolar Transistors (BJT)

137 products

IGBT Transistors

42 products

SMD Transistors

3 products

Related categories

BuzzersIntegrated CircuitsCapacitorsDiodesDIY Electronics ProjectsFlash MemoryMicrocontrollersPotentiometersCrystal OscillatorsVoltage Regulators and Power CircuitsRelaysResistors
368 results

368 results

12…23

Choosing the right transistor

Start with the function. A small signal (amplification stage, relay driving, logic interface) is handled very well with a bipolar in TO-92 such as the BC547, the 2N2222A, the 2N3906 or the 2SC1815. To switch a significant current with low losses, a MOSFET is more suitable: the IRFZ44N or the IRLZ44N for N-channel, the AO3401 in SOT-23 for P-channel.

Then check three figures given in the part number:

  • Voltage: the collector-emitter (or drain-source) voltage must clearly exceed that of the circuit, especially with an inductive load.
  • Current: keep margin over the actual current, and consider cooling on a TO-220.
  • Drive: a bipolar is current-driven through a base resistor, a MOSFET is voltage-driven. With a 3.3 V or 5 V output from a microcontroller, choose a logic-level model such as the IRLZ44N, otherwise add a driver.

For mains and high currents at high voltage, look at the IGBTs. The DIAC DB3, meanwhile, is used to trigger a triac in dimmers and ballasts. Also consider the pinout: it differs between TO-92, TO-126 and TO-220. The rest of the catalog can be found under Components.

Frequently asked questions

What is the difference between a bipolar transistor and a MOSFET?

The bipolar is current-driven through its base and keeps a voltage drop of about 0.2 to 0.7 V when conducting. The MOSFET is voltage-driven on its gate and has a very low on-state resistance, which means less heating in power switching.

Which transistor to drive a motor or a relay with an Arduino?

For a relay or a small load, a bipolar such as the 2N2222A or the BC547 with a base resistor is enough. For a motor drawing several amps, choose a logic-level N-channel MOSFET such as the IRLZ44N, with a flyback diode across the load.

How to tell an NPN from a PNP?

The NPN conducts when the base is more positive than the emitter and is placed on the ground side of the load; the PNP conducts with a more negative base and is placed on the supply side. In practice, a multimeter's diode test between base and emitter shows the direction.

What is the DB3 DIAC used for?

It is a bidirectional component that only conducts beyond a breakover voltage of about 32 V. It is used to generate the gate pulse of a triac in light dimmers and ignition circuits.

Why do two transistors with the same current rating not have the same price?

Price depends on voltage rating, on-state resistance, package and manufacturer. A high-voltage power part in TO-220 or an IGBT logically costs more than a small-signal part in TO-92.