Panasonic V-series caps

C

Chris Carlen

Guest
Hi:

I'm stocking drawers with PTH caps and noticed the new V series in
DigiKey's catalog. These stacked metallized film caps are a bit smaller
than the B series polyester. A nice compromise for 5% caps if the size
of B is too much, but COG ceramics up to 10nF are too expensive.

Oh, but if tempco is critical then COG is worth the price since it's
about 30-40ppm vs. 200ppm. I avoid doing timing critical stuff with
analog anymore, so for drawer stuffing, this doesn't matter much.

Any horror stories about this V series?


Good day!




--
_______________________________________________________________________
Christopher R. Carlen
Principal Laser/Optical Technologist
Sandia National Laboratories CA USA
crcarleRemoveThis@BOGUSsandia.gov
NOTE, delete texts: "RemoveThis" and "BOGUS" from email address to reply.
 
Chris Carlen wrote:
Hi:

I'm stocking drawers with PTH caps and noticed the new V series in
DigiKey's catalog. These stacked metallized film caps are a bit smaller
than the B series polyester. A nice compromise for 5% caps if the size
of B is too much, but COG ceramics up to 10nF are too expensive.

Oh, but if tempco is critical then COG is worth the price since it's
about 30-40ppm vs. 200ppm. I avoid doing timing critical stuff with
analog anymore, so for drawer stuffing, this doesn't matter much.

Any horror stories about this V series?
I have none. I have had very good results with them, and, as you say,
they save a lot of board space.

--
John Popelish
 
In article <d0q2st01unm@news3.newsguy.com>,
Chris Carlen <crcarleRemoveThis@BOGUSsandia.gov> wrote:
Hi:

I'm stocking drawers with PTH caps and noticed the new V series in
DigiKey's catalog. These stacked metallized film caps are a bit smaller
than the B series polyester. A nice compromise for 5% caps if the size
of B is too much, but COG ceramics up to 10nF are too expensive.

Oh, but if tempco is critical then COG is worth the price since it's
about 30-40ppm vs. 200ppm. I avoid doing timing critical stuff with
analog anymore, so for drawer stuffing, this doesn't matter much.

Any horror stories about this V series?
I have no problem specifically with "V series" but in general to all
Panasonic capacitors, I try to avoid designing them in. I've designed
Panasonic capacitors in, in the past. It almost never fails that within a
year or two you can't get the exact same part. I was forever getting
questions from the purchasing department about changing the design or
doing a life time buy.

I also don't consider the price of COG parts high enough to look for a
different option in most cases. The size issue is where film capacitors
sound like an advantage. You have to be careful what else is on the PCB
with the film caps. If you are soldering large power parts down,
maintaining the temperature profile for the film caps can be very hard
while getting the power parts soldered.

The failure and defect rate of SMT film capacitors seems to be higher than
COG by a large factor.
--
--
kensmith@rahul.net forging knowledge
 
Ken Smith wrote:
In article <d0q2st01unm@news3.newsguy.com>,
Chris Carlen <crcarleRemoveThis@BOGUSsandia.gov> wrote:

Hi:

I'm stocking drawers with PTH caps and noticed the new V series in
DigiKey's catalog. These stacked metallized film caps are a bit smaller
than the B series polyester. A nice compromise for 5% caps if the size
of B is too much, but COG ceramics up to 10nF are too expensive.

Oh, but if tempco is critical then COG is worth the price since it's
about 30-40ppm vs. 200ppm. I avoid doing timing critical stuff with
analog anymore, so for drawer stuffing, this doesn't matter much.

Any horror stories about this V series?


I have no problem specifically with "V series" but in general to all
Panasonic capacitors, I try to avoid designing them in. I've designed
Panasonic capacitors in, in the past. It almost never fails that within a
year or two you can't get the exact same part. I was forever getting
questions from the purchasing department about changing the design or
doing a life time buy.

I also don't consider the price of COG parts high enough to look for a
different option in most cases. The size issue is where film capacitors
sound like an advantage. You have to be careful what else is on the PCB
with the film caps. If you are soldering large power parts down,
maintaining the temperature profile for the film caps can be very hard
while getting the power parts soldered.

The failure and defect rate of SMT film capacitors seems to be higher than
COG by a large factor.
I have had the sme problems with panasonic, and the converse problem -
can get a cap but cant get its data sheet (old stock 100V FC series).

I have melted PPS caps before :( And not just during soldering either :(

I once looked at designing a 100uF 200V NPO cap into a smps, but it cost
$1/uF + $0.5/V, so I looked at Paktrons Capstick, which although 10x
cheaper was still 10x too much.

Cheers
Terry
 

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