What are the specifications of varactor diode?
What are the specifications of varactor diode?
The actual capacitance range for a varactor diode depends upon a number of factors: the area of the junction; the width of the depletion region for a given voltage, etc. It is found that the thickness of the depletion region in the varactor diode is proportional to the square root of the reverse voltage across it.
What is the general range of varactor diode capacitance?
A four-to-one capacitance range is not unusual. In fact, a typical varactor diode can vary from 60 pf at zero bias to 15 pf at 20 V. With careful manufacturing, however, the capacitance range can be increased to ten-to-one.
What are the applications of varactor diode?
Applications. Varactors are used as voltage-controlled capacitors. They are commonly used in voltage-controlled oscillators, parametric amplifiers, and frequency multipliers. Voltage-controlled oscillators have many applications such as frequency modulation for FM transmitters and phase-locked loops.
When to choose a varactor diode for a circuit?
When choosing a varactor diode from the information on the datasheet, the varactor specifications need to be carefully assessed to see whether its performance meets the needs for the circuit in which it is intended for uses. In view of the fact that the varactor diode is a semiconductor diode, many parameters are the same as those of other diodes.
Why is reverse breakdown voltage important for varicap diodes?
Varactor reverse breakdown specification The reverse breakdown voltage, V B of a varactor diode is an important specification because the voltages which can be used to drive these diodes to provide the required range of capacitance can be quite high in some instances.
Do you need to know the varactor specs?
As the varactor requirements can be a balance between several competing factors it is necessary to understand the specifications and what they mean.
How is the reverse breakdown voltage of a varactor measured?
The reverse breakdown voltage is normally measured at the point where there is 10µA of reverse current. As varactors are often driven from a high impedance source, this limit is very acceptable. When selecting a varactor diode, the reverse breakdown voltage parameter V B is of importance and the diode should not be run too close to the maximum.
