What is 1N4732A Zener Diode : Pin Configuration & Its Working

A Zener Diode or a breakdown diode is one kind of semiconductor device & it operates in the reverse direction. Once the voltage across its terminals is upturned then the potential achieves the Zener Voltage & the junction will break down to allow the flow of current in a reverse way, so this effect is called the Zener Effect. This article discusses an overview of 1N4732A Zener Diode and its working.


The flow of current in the Zener diode is not only from anode terminal to cathode but also in the reverse direction on attaining the Zener voltage. So because of this functionality, these semiconductor diodes are most frequently used in different applications.

What is 1N4732A Zener Diode?

This 1N4732A Zener diode is available in the Through-hole package. This kind of diode is applicable in different circuits like a crude voltage regulator & a protection circuit. However, it is very significant to keep in mind that this diode must be connected with a Zener resistor always in any application.

1N4732A Zener Diode
1N4732A Zener Diode

The operating voltage of 1N4732A 4.7V Zener Diode is 4.7V and as compared to other kinds of Zener diodes, it is used as a reference element within voltage regulation. So it is used in the applications of switching & clipper circuits.

Pin Configuration

1N4732A Zener diode pin configuration is shown below. This diode includes two pins where each pin and its function are discussed below.

1N4732A Pin Configuration
1N4732A Pin Configuration
  • Pin1 (Anode): The flow of current is always throughout the anode
  • Pin2 (Cathode): The flow of current is always throughout the cathode

Features & Specifications

The features & specifications of the 1N4732A Zener diode include the following.

  • Through-hole type package
  • Reliability is high
  • The required voltage to operate the diode is 4.7V
  • The type of case is Do-41 glass
  • Tolerance is ± 5%
  • Weight is 0.35g
  • Dissipation of power is 1.0 Watt
  • Storage temperature ranges from -65oC to 175 oC
  • Characteristics are extremely sharp reverse
  • Zener Current is 10 uA
  • Zener Impedance is 8 Ohms
  • Operating temperature range is – 65 C to + 200 C
  • Axial termination style
  • Single configuration
  • 310 mg unit weight
  • Test Current is 53 mA
  • 5.2 mm length
  • Bulk packaging
  • Reverse current is 10 uA
  • 1N4732A series
  • 2.72 mm Diameter

Alternative zener diodes are 5.1V Zener, 7.5V Zener, 6.8V Zener & 15V Zener

How to Choose a Zener Diode?

As compared to common rectifier diodes, a Zener diode is one kind of diode, however, is used for a completely different purpose. These diodes are used in different circuits like crude voltage regulators and protection.

Before selecting a Zener diode, we need to consider different parameters for your application. Like power dissipation & Zener Voltage. The Zener voltages mainly come into view across the diode once a high reverse potential voltage is given to it.

Zener voltage within regulator circuits will be adjusted whereas, in protection circuits, this voltage is high as compared to the circuit is defended. The dissipation of power will decide the quantity of current that flows throughout the diode. When the power dissipation is high then the flow of current will be high.


How to use 1N4732A Zener Diode

We have already discussed that Zener diode is used mostly in various circuits like protection & a simple voltage regulator circuit but this diode must be used with a Zener resistor within the circuit.

Here, a Zener resistor is a normal resistor, used to restrict the current supply within the circuit. The main function of this resistor is to decide the quantity of current supply throughout the diode otherwise load which is connected to this diode. So, in this way, this diode will be protected from the huge current. If a Zener resistor is not used with a Zener diode then the diode may get damage.

1N4732A Zener Diode Circuit Diagram

Here is the application circuit of 1N4732A Zener diode is shown below. The application circuit like DC Adapter using 1N4732A Zener diode is shown above. The source of power supply used for this circuit is taken from the car battery.

Car DC Adapter Circuit with 1N4732A Zener Diode
Car DC Adapter Circuit with 1N4732A Zener Diode

This circuit works on the operation of the voltage regulator of the Zener diode. The output provided by this circuit is stable like 4.7V. The required components of this circuit mainly include TIP 122, 1N4007, 1N4732A, 470Ω 1W — 1, 100 µF, 470 µF & a 2A Fuse.

The supply provided to this circuit can be taken from the battery of a car. But the capacities and the ratings of batteries of different cars may different. So, a 2A fuse is mainly used for restricting the highest flow of current within the circuit.

Here, the battery supply is directly given to the TIP122 transistor’s collector terminal and it is also provided to the cathode terminal of the diode through the Zener resistor. Here, a diode is allied at the emitter terminal of the transistor to obtain the output.

Car DC Adapter Circuit Working

The simple car DC adapter circuit is designed to charge phones with the help of a car battery. According to the above-shown circuit, the connections are given. The range of o/p voltage from a battery ranges from 12V – 13.5V.

The protection device in the circuit-like fuse will limit the utmost 2A of load current. This circuit uses a 1N4732A Zener diode that has 4.7V of reverse breakdown voltage.

Therefore, the voltage across the diode will be stable. Once this voltage is applied at the base terminal of the TIP122 transistor, then it will be activated & the o/p will be a constant 4.7V.

In the above circuit, the current is approximately 15mA which is very little. So this is not enough to charge the battery of a mobile phone. For increasing the flow of current within the circuit, we need to analyze the power rating of the Zener resistor & Zener diode.

Thus, a simple calculation can be done using some values like 12V input & 4.7 V output. If the o/p current we require is 300mA, the flow of current within the circuit must be approximately 330mA.
The Zener resistance can be calculated like Zr = (12– 4.7) V / 330mA = 22.1ohms. Therefore, a 22 ohms Zener resistor should be selected. For Zener diode’s power rating, the diode’s breakdown voltage is 4.7V & the utmost current within the circuit is approximately 330mA.

Here, the Zener diode power rating can be measured like breakdown voltage that is multiplied through utmost current. So, the power rating of the Zener diode is 4.7V x 330 mA = 1.55Watts. Therefore, better to use a 2W Zener diode for protection purposes.

When the flow of current within the circuit is enhanced, then voltage drop beyond the resistor will also be increased. The resistor’s power rating is also extremely significant.

If the voltage applied to the circuit is 12V & the diode’s breakdown voltage is 4.7V, then voltage drop beyond the resistor is around 7.3V. The maximum current assumed within the circuit is approximately 330mA. As a result, the resistor’s power rating is measured like the following.

Power rating of Zener resistor is 7.3V x 330mA => 2.4W. Therefore, a 3W resistor should be chosen.

Where to use/Applications

1N4732A Zener diode is used in different applications which include the following.

  • This kind of more zen diode is used in the circuits of voltage protection
  • It can be used like a less current voltage regulator
  • It gives protection to Input voltage for ICs or Microcontrollers
  • Used in stabilizing circuits of voltage

Thus, this is all about an overview of a 1N4732A Zener Diode. Generally, a Zener diode is a PN junction semiconductor diode and it is operated in the condition of reverse bias. However, a normal PN junction diode that is connected in the condition of reverse bias is not utilized practically like the Zener diode. So, this is a highly doped and specially designed PN junction diode. Here is a question for you, what are the drawbacks of a Zener diode?

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