|Pin No.||Pin Name||Description|
|1||Anode||Current always Enters through Anode|
|2||Cathode||Current always Exits through Cathode|
- Nominal Zener Voltage (VZ): 4.7V
- Power dissipation (PZ): 1300mW (practically 500mW)
- Zener regulator current (IZm): 193mA
- Package: DO-41
Note: Complete Technical Details can be found at the 1N4732A diode datasheet given at the end of this page.
Alternative Zener Diodes
5.1V Zener, 6.8V Zener, 7.5V Zener, 15V Zener
How to select a Zener Diode
A Zener diode is one of the different types of diodes, but is used for entirely different purpose than the common rectifier diodes. They are mainly used in protection circuits or as crude voltage regulators. Let us see how we can select one for your application.
There are two main parameters that are to be checked while selecting a Zener diode for your electronic design. One is the Zener Voltage and the other is Power dissipation. The Zener voltage is the voltage which appears across the Zener diode when a higher reverse potential voltage is applied to it. In regulator circuits it is this voltage (Zener voltage) which will be regulated and in protection circuit it is this voltage (Zener voltage) more than which the circuit is protected. The power dissipation decides the amount of current that can flow through the diode. Higher the power dissipation higher the current can flow.
How to use a Zener Diode
As said a Zener diode will mostly be used in a protection circuit or in a crude voltage regulator circuit. Either way, it very important to remember that a Zener diode should always be used along with a Zener resistor.
A Zener resistor is nothing but an ordinary resistor which is used for current limiting purpose. This resistor decides (limits) the amount of current that can flow through the Zener diode or through the load connected to Zener diode; this was the Zener diode is protected from high current. If this resistor is not used the diode will be damaged due to high current. A simple Zener diode circuit is shown below.
In the above circuit the formulae to calculate the Zener series resistor Rs is shown below
Zener Diode circuit
Rs = (Vs – Vz) / Iz
For a 1N4732A Zener diode the value of Vz is 4.7V and Pz is 500mW as mentioned in specifications above, now with supply voltage (Vs) of 12V the value of Rs will be
Rs = (12-4.7)/Iz Iz = Pz/Vz = 500mW / 4.7V = ~106mA Therefore, Rs = (12-4.7)/106 = 68 ohms Rs = 68ohms (approx)
Applications of 1N4732A Zener Diode
- Used in Voltage protection circuits
- Can be used as low current voltage regulator
- Input voltage protection for Microcontrollers or other IC’s
- Voltage stabilizing circuits
2D representation (DO-41)