Users' questions

Can zener diodes be used in series?

Can zener diodes be used in series?

Zener diodes can be placed in series or parallel with other circuit elements, which includes other Zener diodes. When using Zener diodes in series, the current and voltage distribution will follow Kirchoff’s laws, and you can derive a specific relationship for the voltage and current distribution in your diodes.

How do you calculate the resistor for a zener diode?

Circuit design example

  1. Calculate the difference in voltage across the series resistor. 12 – 5.1 = 6.9 volts.
  2. Determine the resistor current.
  3. Check the Zener diode power dissipation.
  4. Determine the current through the series resistor.
  5. Determine the value of the series resistor.
  6. Determine the wattage of the series resistor.

Does zener diode need resistor?

A power supply has a very low output impedance and a Zener diode has a non-zero impedance. Without a series resistor this means: The voltage across the Zener diode will be higher than specified due to its internal resistance.

Do Zener diodes have resistance?

Zener impedance is the equivalent series resistance of a Zener diode when it is conducting current. It is calculated as a change of Zener voltage, ΔVZ, that occurs as a result of a tiny change in Zener current, ΔIZ. Zener impedance should ideally be zero, but in reality, a Zener diode has some impedance.

Why do you need a series resistor for a Zener diode?

A Zener diode is an electronic component utilised in DC voltage regulator circuits. A series resistor “R” is typically required to produce a voltage drop “V Z ” across the load. In this circuit diagram, the unregulated input voltage is V S, and the regulated output voltage across the load is “V L “, which is the same as that across the diode.

What is the supply voltage for a Zener PD?

Supply Voltage is 12V. Needed Voltage is 6V. You need a Zener Pd=5W to handle the current when load takes no current. Resistor value is (needed Voltage drop)/ (max load current) so in this case 6V/0,1A = 60 ohm.

Can a Zener diode be used as a shunt regulator?

The very simple Zener diode circuit providing the shunt regulator function as shown above is not particularly efficient and is not practicable for many higher current applications. One solution is to utilise a Zener diode circuit that uses a transistor buffer that acts as a series pass transistor.

Which is lower base voltage or Zener voltage?

When choosing the Zener diode voltage, it should be remembered that the emitter voltage will be lower than the Zener voltage by the amount of the base-emitter voltage – about 0.6 volts for a silicon transistor. Another form of Zener diode circuit is an overvoltage protection circuit.