1N4734A - 5.6V Zener Diode
1N4734A Pinout Configuration
Pin No. |
Pin Name |
Description |
1 |
Anode |
Current always Enters through Anode |
2 |
Cathode |
Current always Exits through Cathode |
1N4734A Zener Diode Features
- Nominal Zener Voltage (VZ): 5.6V
- Power dissipation (PZ): 1300mW (practically 500mW)
- Zener regulator current (IZm): 162mA
- Package: DO-41
More technical details can be found in 1N4734A zener diode datasheet attached at the bottom of the article.
Alternative Zener Diodes
4.7V Zener, 5.1V Zener, 6.8V Zener, 7.5V Zener, 15V Zener
How to Select a Zener Diode
A Zener diode is another type of diode, but is used for entirely different purpose. 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 to be checked while selecting a Zener diode. 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 circuits or in a crude voltage regulator circuits. Either way, it is 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 that 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 formula to calculate the Zener series resistor Rs is shown below
For a 1N4734A Zener diode, the value of Vz is 5.9 V and Pz is 500mW as mentioned in specifications above, now with supply voltage (Vs) of 12V the value of Rs will be
Rs = (12-5.9)/Iz
Iz = Pz/Vz = 500mW / 5.9V = ~85mA
Therefore, Rs = (12-5.9)/85 = 71 ohms
Rs = 71ohms (approx)
Applications of Diodes
- 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