V3-0 - Replace 10uF/16V Capacitor by Sanyo type
- Replace 10uF/16V Capacitor by Sanyo type
Discussion
Power_supply.SchDoc:
- JGR: C25 rated voltage is 16V. It's connected to the P12V0, so it will be stressed at 75. I think, as a good policy of design, all components must be bellow of the 50 of theirs rated voltage and dissipation power. This will decrease the failure rate of the board.
- NV: I totally agree with this if we can get the same capacitor value with the same ESR and the same case size (A). In this case, all other capacitors of the same type (i.e. C68) have to be replaced as well. But AVX say in the datasheet that the recommended derating should be less than 80% of the rated voltage. This means that the capacitor can handle up to 12.8V. The only replacement part I found with a quick search is the Kemet T491A106M020AT, but its ESR is too high (5 Ohm). If we want to use a B case capacitor of the same type, some components have to be displaced, and whole manufacturing data has to be redone (version 4).
- EB: Leave design as is. According to the above
(http://www.avx.com/docs/catalogs/tcj.pdf), we are within the
recommended derating. Also, this particular board does not get hot.
In the Fine delay design that really heats up, we have used specific
capacitors from Sanyo for their good life-time under high
temperature operation. C25 is 10uF, 16V and could be replaced by
this type that is used on the Fine Delay card:
SANYO 16TQC10M ±20% 10uF 16V ESR 0R1 Solid Tantalum Chip Capacitor. Type B.
Unfortunately the 16TQC10M is a Type B package (1210) and not Type A (1206).
(The other type we use is
SANYO 10TPB47M ±20% 47uF, 10V ESR 0R07 Tantalum Solid Capacitor with Conductive Poly-mer. Type B.)
Recommend to change in a future version. - JGR: Maybe we can use X7R capacitors like this one (or
similar):
http://www.digikey.es/product-detail/en/C3216X7R1E106M/445-7706-1-ND/2733778
X7R capacitors have low ESR and are cheaper than tantalum or aluminium capacitors. Some DCDC applications need a minimal ESR, but I think this isn't the case. - NV: I agree replacing the 10uF by the X7R as you propose.
- EB: Leave design as is. Recommend to change in a future version. See 2.3