Replacing BAR19 diode (a RF project)

Hi,

I need to replace BAR19 diodes (RF schottky diode) which are obsolete and I do not have them. I have found this diode (at Mouser.com) from Agilent/Avago:

5082-2835 (Mouser order code 630-5082-2835).

Do you think I can use them as a replacement for BAR19 ? I am attaching both datasheets, the Avago datasheets contains info for a few different diodes, 2835 is one of them.

Thanks,

Petr

petrv said:

Hi,

I need to replace BAR19 diodes (RF schottky diode) which are obsolete and I do not have them. I have found this diode (at Mouser.com) from Agilent/Avago:

5082-2835 (Mouser order code 630-5082-2835).

Do you think I can use them as a replacement for BAR19 ? I am attaching both datasheets, the Avago datasheets contains info for a few different diodes, 2835 is one of them.

Thanks,

Petr

Click to expand...

It depends on how the diode is being used. In general the 2835 looks like a reasonable substitute, but they specify it at only 10mA of forward current, while the BAR19 is ok up to 30 mA. Capacitance is the same, which is good, and forward voltage is about the same. Seems like the main concern is forward current.

If capacity (10p/V) isn't an issue you might try BAT85 (200mA).

Thanks for your answers. The diode is used for detection of high frequencies signal - must work well until 800 MHZ, preferably until 1300 MHz. The current is not issue here (it is very low) but the diode capacitance definitely is very important and should be as small as possible. As the datasheet says capacitance around 1 pF for both diodes I believe this is OK, but I don't have much experience working with so high frequencies to be sure.

For an optimum solution, I can recommend Schottky diodes from Skyworks. They have several specifically for use as detectors, including the SMS1546-005 in your choice of five different packages. Capacitance is around 0.6 pF for this type.

Seems a good choice looking at the datasheet of SMS1546-005 but the problem is where to buy them (Mouser, Digikey -> 0 results) especially when I need a just a few pieces and not 5000 or 10000.

I have received the Avago diodes from Mouser in the meantime so I guess I'll try them.