2N3704 transistor

2N3704 transistor
2N3704 transistor

2N3704 transistor electrical specification

  • 2N3704 is an NPN bipolar junction transistor device
  • Collector to emitter voltage is 30V
  • Collector to base voltage is 50V
  • Emitter to base voltage is 5V
  • Collector current is 500mA
  • Power dissipation is 625mW
  • DC current gain is 100 to 300hFE
  • Current gain-bandwidth (FT) is 100MHz
  • Junction temperature is between -55 to 150℃
  • Collector to emitter saturation voltage (VCE (SAT)) is5 to 1V
  • Thermal resistance, junction case is 3℃/W

2N3704 transistor Pinout

2N3704 transistor Pinout
2N3704 transistor Pinout
Pin Number Pin Name Description
1 Emitter  Current flows through the emitter
2 collector Current flow through the collector 
3 Base   Base is used to trigger the transistor


2N3704 transistor package

The 2N3704 NPN BJT transistor has a TO-92 package, it is a general-purpose device package.

The TO-92 package is made with a mixture of epoxy/plastic materials, these materials have good heat resistance and are also very compact as an electronic component.

Marking the case

This transistor component had a “2n3704” marking on its case

2N3704 transistor electrical specification description/ application

In this section, we try to explain the electrical specifications of the 2N3704 transistor, the characteristics description helps us to know about this transistor device for its usage at the circuit.

Voltage specs

The terminal voltage specs of 2N3704 transistor are collector to emitter voltage is 30V, collector to base voltage is 50V, and emitter to base voltage is 5V.

The collector to emitter saturation voltage is 0.5 to 1V.

The voltage specifications of this transistor show that it is a general-purpose transistor device mainly used for amplification and switching applications.

Current specs

The collector current value is 500mA, the current value indicates the load capacity of the transistor.

The load capacity of the transistor shows that these transistors had driver applications.

Dissipation specs

The power dissipation of the 2N3704 transistor is 625mW, it is the power dissipation of the device.

Current gain specs

The current gain value of the 2N3704 transistor is 100 to 300hFE, this is why these transistors are used for low power amplifiers and switching applications.

Transition frequency

The bandwidth transition frequency value of the 2N3704 transistor is 100MHz, it is the frequency range of the transistor.

Junction temperature

 With the junction temperature of -55 to 150℃, the heat capacity of the transistor is mainly dependent on the case.

The TO-92 transistor package had a medium temperature capability.

Thermal resistance

The thermal resistance of the 2N3704 transistor case is 83.3℃/W

2N3704 transistor DATASHEET

If you need the datasheet in pdf please click this link

2N3704 transistor equivalent

The transistors such as 2SC1318, 2SC1384, 2SC3918, 2SD863, 2SD1347, PN3643, 2SC3922, and KTC1008 are the equivalent of 2N3704 transistors.

The electrical specifications of these transistors are almost similar to the 2N3704 transistor, we can easily replace them in circuits.

But we need to check and verify the PINOUT details of each transistor before the replacement process.

2N3704 vs 2SC1959 vs PN3643

In the table, we try to list the electrical specifications of 2N3704, 2SC1959, and PN3643 transistors.

Collector to base voltage (VCB)     50V35V60V
Collector to emitter voltage (VCE)30V30V30V
Emitter to base voltage (VEB)5V5V5V
Collector to emitter saturation voltage (VCE (SAT))0.5 to 1V0.25V0.22V
Collector current (IC)500mA500mA500mA
Power dissipation625mW500mW625mW
Junction temperature (TJ)-55 to +150°C-55 to +150°C-55 to +150°C
Transition frequency (FT)100MHZ300MHZ        -
Gain (hFE)100 to 300hFE25 to 400hFE20 to 300hFE

The voltage and current specs of each transistor are almost the same, we can use them as the general-purpose component in simple circuits.

The 2SC1959 transistor had a wider frequency range for use at amplifier circuits, the 2N3704 transistor had a medium range.

The DC current gain value of each of these transistors is the same, the gain values show that it is a general-purpose amplification device. 

2N3704 transistor applications

  • General-purpose amplifier circuits
  • Switching load of 300mA
  •  Power supply circuits
  • Relay driver circuits
  • LDR driver circuits

Current adjustable POWER supply circuit using 2N3704

Current adjustable POWER supply circuit using 2N3704
Current adjustable POWER supply circuit using 2N3704

The figure shows the current adjustable power supply circuit, the circuit consists of 741 OP-AMP, 12V Zener diode, and 2N3704 transistor.

The Zener diode will stabilize or regulate the voltage variations they get and passes over to the OP-AMP.

The OP-AMP works as the unity gain voltage follower and the 2N3704 acts as the emitter follower current amplifier stage.

Both these component networks combined to form a voltage and current adjustable power supply using a 2N3704 transistor.

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