Did you know that....
1) VMI offers over 45 different 5kV diodes?
Neither did I! I got to thinking about it because our 5kV diodes are popular devices. The question came up because a customer called and wanted a recommendation. I knew we offered quite a few, but I was surprised to learn there are more than 45 of them. I know because I counted them.
45+ different 5kV diodes sounds intimidating. Fortunately there are a couple of pretty quick questions that can help narrow down the search.
Three main diode characteristics include Vrwm, Io, and Trr (reverse voltage, forward current, and reverse recovery time, respectively). There are more, but these define the device. Different applications have different requirements. As is true with many things in life, the answer to, "What's the best 5kV diode you make?", is, "It depends".
Higher operating frequencies require faster Trr (lower Trr).
Sometimes high operating temperature means you want to add a lot of derating, so even though the application might only use 2kV, if the temperature is high or there are a lot of voltage spikes, using a diode with a higher Vrwm rating can be helpful.
- Current ratings of 5kV diodes range from 40mA up to 2.2A.
- Trr ranges from 30ns to 3000ns.
And then there are the 5kV diodes that have reverse power capabilities, like the ZR50SG. It's a 5kV, standard recovery diode that can handle up to 10mJ of reverse power. The reverse power capability means under arcing conditions or voltage spikes of less than 10mJ, the diode will recover.
High reliability tested and QPL diodes are available too. The options include axial-leaded glass body diodes tested to different levels of processing. Military grade diodes use the JANTX, or JANTXV prefix such as JANTXV1N6525.
2) Termination and Package Styles Abound?
The second surprising thing about VMI's 5kV diodes is the variety of termination and package styles.
Termination styles include surface mount, through-hole, and formed-lead.
Package styles include glass, epoxy, and molded bodies.
There are various combinations too, like a surface mount, molded diode (SMF6533 for example), and a formed-lead glass body diode, like the 1N6517LL.
3) VMI's Diodes are "Multi-junction"?There are many surprising things about high voltage diodes, not the least of which is that any diode over approximately 1kV is going to have more than one junction. Essentially a 5kV has multiple die 'stacked' together in series. The die come from the same wafer so differences are minimized. Stacking silicon die is about the only way to achieve high voltage blocking capabilities.
Get Your List of 5kV Diodes
It's easy to get your list of VMI's 5kV diodes. Next time you visit VMI's website, click on the "Diode Search" button in the upper right corner. When the search page appears, select 5kV in the Vrwm (V) pull-down menu, and press the 'Search' button.
The results page includes a summary of all the 5kV diodes in pdf format, and links to their data sheets. You can save the results page to your desktop, or print it out.
And if you're not sure what you need, give us a call. We'll help you make the right selection for your application.