>but I am not quite clear on the passives
>(what is a 0805 resistor? etc.)

You are into a joyous area.

You say that you more or less know the packages for chips. Don't believe it,
if you think that the number of packages for DIL chips is bewildering, then
wait till you get into SMD. The variations on packages is amazing. Always
check the datasheet carefully to make sure that it describes exactly which
package the chip is in. I have had datasheets which describe every package
except the one the chip actually came in. If possible look for a JEDEC
outline number on the package description.

Your question on passives. The package you have listed above is the plan
dimensions in hundredths of an inch. I.e. the component is 0.08" x 0.05" in
size. You will find that resistors come in a number of standard physical
sizes, the largest normally being 1208, and I believe the smallest is
something like 0201. The very smallest sizes are considered a health hazard
for handling, as they are small enough and light enough to behave like dust
and be sucked into your lungs as you breath. These require a dust mask while
handling. However I very much doubt you will be dealing with them :) 1208
and 0805 are the two most likely sizes you will deal with.

Ceramic capacitors tend to come in the same size packages as resistors.
However for some strange reason these never seem to have the value marked on
them like the resistors do. You need to keep track of these carefully for
this reason.

The next thing you will find is that the package dimensions given above are
the imperial units version. There is an equivalent metric package standard.
For example a 3216 (metric) is the same package as 1208 (imperial). If you
find a component described as a package you don't recognise, check if it is
a metric one.

Tantalum electrolytic capacitors come in a range of about 5 or 6 package
sizes. These are A through F, with package E being the same footprint as D,
but a higher profile. AFAIK these packages are standard across all tantalum
manufacturers. It is worth going to the website for AVX or Kemet and getting
a datasheet to use as a reference. Also watch the component pricing on
these. As the value and voltage climb, the price seems to go up
exponentially. If looking for power supply filtering capacitors you are
probably better off using aluminium electrolytics, but they come in very
different packages to the tantalums.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body