JB Capacitor temperature coefficient for nvme data lanes good? - Page 1
Forum section: electronics / beginners

author: The Mad Atheist
author_rank: Newbie
timestamp: July 17, 2021, 02:26:05 pm
content: Hi, I'm installing the 2nd m.2 components to my MSI GL65 Leopard 10SEK-022 laptop that MSI decided to not put on.Looks like I can only get 0201 220nF caps with JB, similar to X5R ( -25°C ~ 85°C ) temp coefficients. Someone recommended X7R or C0G ones.Any feed back for these in this use case?https://www.digikey.com/en/products/detail/C0603JB1A224K030BB/445-10754-1-ND/3952420?itemSeq=371312745--------OLD POST INFO, DISREGARD-------Specs say 220np 10v 0201, but the smallest I can find on their site or 25v.https://www.digikey.com/en/products/detail/GJM0335C1ER22WB01D/490-17301-1-ND/7602300?itemSeq=371149156Would there be any issues using a higher voltage for the data lanes?thanks, d.

author: The Mad Atheist
author_rank: Newbie
timestamp: July 17, 2021, 02:28:28 pm
content: Closer pic of C1572-C1579.

author: daqq
author_rank: Super Contributor
timestamp: July 17, 2021, 07:35:47 pm
content: There shouldn't be any issues with higher voltage, but are you sure you got the right capacitor? 0.22pF sounds too low for, well, anything? IIRC the recommended coupling capacitor for PCiE were in the tens/hundreds of nF region. Are you sure it's not supposed to be 220nF or some such?

author: The Mad Atheist
author_rank: Newbie
timestamp: July 17, 2021, 10:08:48 pm
content: Whoops, used a P instead of a F.Yes, the caps I need are 220nF or .22uFEdit, wow, glad you caught that!Thx, d.

author: The Mad Atheist
author_rank: Newbie
timestamp: July 18, 2021, 10:26:28 pm
content: OK, finally fixed the error.Looks like I can only get 0201 220nF caps with JB, similar to X5R ( -25°C ~ 85°C ) temp coefficients. Someone recommended using X7R or C0G ones.Any feed back for these in this use case?https://www.digikey.com/en/products/detail/C0603JB1A224K030BB/445-10754-1-ND/3952420?itemSeq=371312745

author: TimFox
author_rank: Super Contributor
timestamp: July 18, 2021, 10:29:51 pm
content: X7R and X5R are very similar for your case, and 220nF C0G capacitors are expensive and bulky, so you need a very good reason to use C0G for your application. I’m quite sure that 220nF C0G does not exist in 0201. The last ones I bought (for a good reason in an analog application) were 1812 or some such size.

author: The Mad Atheist
author_rank: Newbie
timestamp: July 19, 2021, 07:05:06 pm
content: Thanks for the reply, I saw the temp curve and thought I ask to be safe.

author: The Mad Atheist
author_rank: Newbie
timestamp: July 19, 2021, 07:32:27 pm
content: Might as well post my part list for review just in case I have another error or missed something.thx, d.0.22 µF ±10% 10V Ceramic Capacitor JB 0201 (0603 Metric) for C1572-C1579.The m.2 connector pads are 1mm in length so the cap pads should be .6mm, 0201 size.https://www.digikey.com/en/products/detail/C0603JB1A224K030BB/445-10754-1-ND/3952420?itemSeq=3713127451uf for C1570 coupling. 0603https://www.digikey.com/en/products/detail/C0603C105K4RAC7411/399-C0603C105K4RAC7411CT-ND/12701838?itemSeq=371148843100nf for C1571 coupling. 0402https://www.digikey.com/en/products/detail/C0402C104K8RACTU/399-3520-1-ND/789660?itemSeq=371148883M2x0.4 Pan Head Machine Screw Phillips Drive Nylonhttps://www.digikey.com/en/products/detail/50M020040G004/145-50M020040G004-ND/11638015?itemSeq=371151403THREADED STANDOFFhttps://www.digikey.com/en/products/detail/SM3ZS067U410-NUT1-R1200/670-2865-1-ND/5955849?itemSeq=371262501Alternative THREADED STANDOFFhttps://www.digikey.com/en/products/detail/9774025243R/732-7079-1-ND/5320684?itemSeq=37126631067 Position Female Connector M.2 (NGFF) Mini Card Gold 0.020" (0.50mm)https://www.digikey.com/en/products/detail/1-2199230-6/A118046CT-ND/4729812?itemSeq=3713119122.60mm Thermal pad to ?disperse heat" to MOBO end. Other m.2 drive has one under it's drive.https://www.digikey.com/en/products/detail/57GF20500260500100/903-57GF20500260500100-ND/14325461?itemSeq=371260719