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sorry for poor quality

I have about 100 of these very small diodes, approximately 1/3 smaller than the diameter of a dime. They are all umarked and all I know is that their voltage drop is about .55v to .62v. I am thinking they are silicon based diodes, but I am not for sure. Any ideas? Thanks.

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  • \$\begingroup\$ why do you need that and what specific parameters do you want to know? \$\endgroup\$ – Gregory Kornblum Jun 21 '17 at 6:45
  • \$\begingroup\$ I would like to use them in a vco that operates from 100Mhz to 200Mhz. Most important parameters would be switching speed and capacitance vs. backwards voltage. \$\endgroup\$ – user2761204 Jun 21 '17 at 6:52
  • \$\begingroup\$ backwards voltage is easy to test- just bias it reversely and see when it brakes down. then take 50% of it to be sure. Capacitance- relatively easy- charge/discharge with high speed mosfet through big resistor. \$\endgroup\$ – Gregory Kornblum Jun 21 '17 at 6:56
  • \$\begingroup\$ So you want to use them as a varactor? \$\endgroup\$ – Spehro Pefhany Jun 21 '17 at 14:13
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Try them and see if you get problems. Nobody is going to make a positive ID on them without a bit of guesswork. My best guess is that it is a 1N914 or 1N4148 diode but I could be completely wrong. The voltage reading you measured depends entirely on what current you passed through the device. The 1N4148: -

enter image description here

So if you passed 1 mA then 0.55 to 0.62 volts is about right for a diode of this type. Also, how do you know they are not zener diodes? Diodes cost pennies and my personal advise is throw them away and buy the ones you need.

Take my word for it - you will be saving yourself time and time = money.

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  • \$\begingroup\$ Thanks! I will check to see if they are zeners with a simple voltage controller. I'll keep this question open in case I do identify them. \$\endgroup\$ – user2761204 Jun 21 '17 at 7:06

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