My diode is:



Diode Type:Standard Recovery; Repetitive Reverse Voltage Max, Vrrm:400V; Forward Current, If(AV):1A; Forward Voltage Max, VF:1.1V; Forward Surge Current Max, Ifsm:30A; Operating Temperature Ran 78K2120;

Source, please, search for 78K2120.


  1. What does "78K2120" mean?
  2. According to the new reply, it is an identifier but what does it mean? Why is it chosen? Does it contain some information except being a random identifier?
  3. Is there some standard, seen too many manufacturers just throwing similar lines but with different meaning?

78K2120 is the Newark product code for that diode.


Google FTW.

That diode's temperature range is -50~+150 degrees celsius. Data sheet: http://www.vishay.com/doc?88503; Farnell Australia (au.farnell.com) part number 1421919.

  • \$\begingroup\$ These are the same numbers I found. \$\endgroup\$ – Kortuk Jun 9 '10 at 14:37
  • \$\begingroup\$ it is still open what does it mean and why is it chosen? -- cannot believe it is just a random identifier \$\endgroup\$ – hhh Jun 9 '10 at 15:23
  • \$\begingroup\$ the 78k probably is a number used for all diodes, but yes, it is a random identifier. It is based on some internal system, but it is random as far as you will ever know and does not correlate to device function. \$\endgroup\$ – Kortuk Jun 9 '10 at 16:04
  • 1
    \$\begingroup\$ My name Kortuk identifies me, it does not let you know how awesome I am unless you have used a kortuk before and found out that, on the whole, people with the name kortuk are winners. \$\endgroup\$ – Kortuk Jun 9 '10 at 16:13

I contacted Newark and their answer is: "Our part# does not mean anything in relation to the specs on the manufacturer part.". So it is apparently about book-keeping.

  • 2
    \$\begingroup\$ yes, a part number is for book keeping. They are about finding parts in stock, they have no bearing on function of the device. a well design system has some connection between device and assigned part number, like the 78k might mean it is a diode, but that is it. \$\endgroup\$ – Kortuk Jun 9 '10 at 16:03
  • \$\begingroup\$ cannot understand down-vote, have to label question as beginner. The thing "78K2120" is similar to smallCaps' markings such as "104 K5K", "154 C1K", "104K X7R50" and probably many other markings -- easy for beginners to overlook! \$\endgroup\$ – hhh Jun 9 '10 at 19:30

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