Pin Diode Switching Characteristics

The intrinsic layer among the p n layers increases the space between them.

Pin diode switching characteristics.

The intrinsic layer between the p and n regions increases the distance between them. Some of the pin diode characteristics are given in the points below. The pin diode is a special diode which can be configured as an rf switch. The pin diode makes an ideal rf switch.

At a low enough frequency the stored charge can be fully swept and the diode turns off. A pin diode has two switching speeds from forward bias to reverse bias tfr and from reverse bias to forward bias trf. As we already discussed that a pin diode offers a lower value of capacitance due to the larger distance between p and n region. The wide depletion layer provided by the intrinsic layer ensures that pin diodes have a high reverse breakdown characteristic.

Light striking the crystal lattice can release holes and electrons which are drawn away out of the depletion. A microwave pin diode is a semiconductor device that operates as a variable resistor at rf and microwave frequencies. Characteristics of pin diode. The pin diode obeys the standard diode equation for low frequency signals.

The pin diode is used as a high voltage rectifier. Pin diode possesses very low reverse recovery time. The diode obeys standard diode equation for all the low frequency signals. At higher frequencies the diode looks like an almost perfect very linear even for large signals resistor.

The intrinsic layer in the diode offers a partition between the both the layers permitting higher reverse voltages to be tolerated. Pin diode is formed by sandwiching intrinsic layer high resistivity about 0 1 ω m between p type and n type semiconductor to create an electric field between them. The diode characteristic that affects tfr is τ carrier lifetime. The pin diode is used as an ideal radio frequency switch.

A pin diode is a current controlled device in contrast to a varactor diode which is a voltage controlled device. It has a wide undoped intrinsic semiconductor region i sandwiched between a p type semiconductor p and an n type semiconductor region n hence the pin designation. The pin diode can be used as a high voltage rectifier. The capacitance of pin diode is independent of bias level as the net charge is said to be very less in the intrinsic layer.

The value of tfr may be computed from the forward current if and the initial reverse current ir as follows. When only a small reverse potential is applied the depletion region gets totally depleted. Varactors diodes are design with thin epitaxial i layers for a high q in the. The p i n diode has a relatively large stored charge adrift in a thick intrinsic region.

This is unlike a standard diode which has no intrinsic region. The intrinsic region provides a greater separation between the pn and n regions allowing higher reverse voltages to be tolerated.