Jump to content
Electronics-Lab.com Community

varactor diodes

Kevin Weddle

Recommended Posts

Does a varactor diode release any stored energy when the voltge is removed, like a capacitor or inductor does?

A varactor diode has a very low capacitance of 2pF for ones used to tune very high frequencies to about 200pf to tune AM broadcast band radios. This is an extremely small amount of capacitance that can hold a charge because the diode is reverse-biased and therefore does not conduct but the charge cannot power anything.
Link to comment
Share on other sites

A 200pF capacitor can discharge relatively slow with a large resistance.

22M is the highest resistor value in my collection. 200pf discharges completely (5 time-constants) by one in only 22 milli-seconds. That is not slow.
You can make the discharge faster by increasing the reverse bias voltage to reduce the capacitance value.
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...