11 Feb
2014
11 Feb
'14
5:17 p.m.
On Feb 11, 2014, at 9:49 AM, Vincent Slyngstad <vrs at msn.com> wrote:
From: allison: Tuesday, February 11, 2014 6:05 AM
The bright side is that they're common as dirt and about as cheap, so if
you're willing to invest some time and effort getting intimate with a
multimeter, you can buy a thousand of them and bin them for voltage drop
yourself. 1N914/4148 (to my knowledge, they're basically identical) is
usually specified for "I need a diode and don't expect to blow it up",
so the characteristics aren't usually all that tightly controlled.
On 02/11/2014 07:49 AM, Michael Thompson wrote:
My understanding of the difference between a D662 and a D664 is that the D664 is supposed
to be a fast switching diode with a low forward voltage drop. The D662 is a similar
diode, but requires a known, fairly high forward voltage drop. (I'd recommend select
1N914 or 1N4148 for the D662, but only some manufacturers have forward voltage drops
of 0.75V.) Unfortunately, forward voltage drop doesn't seem to be a thing that part
numbers of modern switching diodes routinely control. The RICM needs to repair a S603 triple pulse
amplifier flip-chip. The
failed diode is listed as a DEC D-664. The DEC enthusiast cross-reference
lists show it as a 1N3606. These diodes are nearly impossible to find. Can
someone recommend a substitution for the 1N3606 diode?
A quick lookup suggests that 1n914 or 1n4148 are suitable choices. These are
very common fast switching doides. The D664, however, wants the forward drop as low as
possible. Some 1N914 and 1N4148 will fit the bill, but others won't. If you are
looking for a general purpose substitution (rather than a specific application), the
1N4154 should work well. (When I studied the issue, I didn't find any manufacturers
of 1N4154 which had high forward voltage drops.)
If you're looking for low forward voltage drops, you could also try a
Schottky diode, which also tend to be fairly fast. Some may be hard
to find in through-hole, but depending on how worried you are about
visual authenticity, you could wire up some surface-mount packages
either with actual wires or with a tiny PCB jig.
- Dave