1N4002 Diode : Pin Configuration & Its Applications

The general purpose diode like the 1N4002 rectifier diode comes under the 1N400x series family. The diodes from this series are range from 1N4001 to 1N4007. Its blocking voltage mainly changes from 50 V – 1000 V. These diodes are normally utilized in AC adapters within household appliances, rectification purposes within electronic appliances & other applications like voltage boosting, voltage blocking, etc.


This article discusses an overview of the 1N4002 Diode which includes its pin configuration, features, circuit working & its applications.

What is 1N4002 Diode?

A diode is a two-terminal component that allows the flow of current in one direction only from anode to cathode terminal. Here, a grey bar on the diode signifies the cathode terminal.

1N4002 diode is a general-purpose diode from the 1N400x series. This is an axial lead Si rectifier arranged in a plastic case & it can be mounted to any place. In addition, these series diodes are very popular and used by electronic beginners, engineers, students, workers, etc.

The features of this diode will make to use in different electronic applications like less cost, 1A forward current, tiny package, power dissipation is 3 Watt, etc. Thus this diode is used where less than 1A circuits are designed and the negligible reverse current is 5uA. Thus this diode is used where less than 1A circuits are designed and the negligible reverse current is 5uA.

Pin Configuration

The pin configuration of the 1N4002 diode is shown below. This diode includes two pins where each pin with its functionality is discussed below. The schematic symbol of the 1N4002 diode is shown below. The cathode terminal of this diode is marked through a band on the diode’s body. It permits the current supply to flow throughout in only one way like from the anode terminal to the cathode.

1N4002 Rectifier Diode Pin Configuration
1N4002 Rectifier Diode Pin Configuration
  • Pin1 (Anode): The current flow direction is always through the anode terminal
  • Pin2 (Cathode): The flow of current will exist throughout the cathode

Features & Specifications

The features and specifications of the 1N4002 diode include the following.

  • Forward current is average like 1A
  • High current capacity
  • Peak current with non-repetitive is 30A
  • Forward voltage drop is less
  • 5uA reverse current
  • Less leakage
  • The reverse voltage of RMS is 70V
  • Junction is diffused
  • Reverse voltage with peak repetitive is 100V
  • Color band specifies the polarity of the cathode end
  • The available package is DO-41 & SMD
  • The range of Operating temperature is -55 to +175 C
  • The type of diode is silicon rectifier
  • Dissipation of power max is 3W
  • Fwd current average is 1000mA
  • Simply cleaned with alcohol, Freon, isopropanol & related solvents

Equivalent 1N4002 diodes are 1N4733A, 1N5408, 1N4148, 1N5822 & Zener Diodes and other possible equivalent 1N4002 diodes are SF12, 1n4148, RL202, HER203, HER202, HER102, HER103, RL203, FR202, 1N4934, FR203 and 1N4935.

How to Protect/Safely Run a 1N4002 Diode

The following points need to consider to protect and safely run a 1N4002 Diode within the circuit.

  • The stable and long-lasting performance of the 1N4002 diode can be achieved through the circuit which works above 100V & always waits under the max values for the constant act.
  • Need to verify the pin-out connections of this diode before connecting in circuits through the soldering process.
  • Load should not be above 1000mA
  • Always maintain the temperature range from below -55 C to above +175 C.

LM338 IC Protection Circuit using 1N4002 Diode

The LM338 IC protection circuit with 1N4002 diode is shown below. In this circuit, an IC regulator and external capacitors are mainly used. In some cases, we need to use a protection diode to avoid low current parts within the regulator IC.

LM338 IC Protection Circuit with 1N4002 Diode
LM338 IC Protection Circuit with 1N4002 Diode

The required components of this circuit mainly include LM338 IC, 1N4002, Capacitors – C1 & C2, Resistors-R1 & R2. Once the two capacitors in the circuit discharge, then it includes less internal series resistance for delivering 20A of spikes whenever they shorted. Even though this surge is short, it includes sufficient energy to harm all the parts of the integrated circuit.

In the circuit, the output capacitor like C1 is connected to the regulator, and then the input shorts & the o/p capacitor will discharge into the regulator’s output. We utilize two 1N4002 diodes like D1 & D2 to absorb the current spike for protecting the regulator circuits.

Here, the discharge current mainly depends on three factors like capacitor value, regulator’s output voltage, and the decrease rate of input voltage.

In the LM138 IC, the discharge lane is throughout a large junction and it can accept a 25A surge without any issue. For 100 uF of output capacitors or below the 15V output, there is no requirement of diodes. So, the bypass capacitor like C2 on the adjustment terminal can discharge throughout a less current-based junction.

When the input or output is shorted then the discharge will occur. So the peak discharge current can be restricted by a resistor within the LM318 IC. For less than 10 mF capacitance or 25V of output voltage, no protection is required. In the above circuit, an LM138 IC with protection diodes is used for the outputs above 25V & maximum output capacitance values.

Where to use/Applications

The 1N4002 rectifier diode is used to design a bridge circuit to change the voltage from AC to DC along with filter capacitors. Except for rectification, this diode can also be used to block voltage spikes, current wherever it is not necessary, voltage boosting, etc.

  • Adapters
  • The reverse polarity issue can be solved
  • AC to DC conversion
  • Controllers for current flow
  • Chargers circuits for battery
  • Signal processing
  • Power supplies of electronic appliances
  • Management of power
  • Components protection
  • HWRs & FWRs
  • Voltage blocking
  • Protection of device
  • Stop the reversing polarity problem

The main difference between 1N4002 and 1N4007 diodes is; the peak repetitive reverse voltage of 1N4007 is 1000V whereas the 1N4001 diode is 50V. Reverse RMS voltage of 1N4007 diode is 700V whereas 1N4001 diode is 35V. The junction capacitance of 1N4007 diode is 8pF whereas for 1N4001 diode is 15pF. Here is a question for you, what is the capacity of max carrying a current of 1N4002 diode?

Thus, this is all about an overview of the 1N4002 datasheet. This diode is from the 1N400x series and it is used to build a bridge circuit for changing the voltage from AC to DC with filter capacitors. This diode is simply replaced through other series of diodes like 1N4003, 4, 5, 6, & 7.