If you're the person who gets handed a requisition for 'KEMET T530' or 'T495' and told to find the best price, I've been there. I oversee roughly $80k in component orders annually across 12 vendors for a mid-sized engineering firm. In the last three years, I've processed orders for everything from passives to enclosures, and I've learned the hard way that a part number is just the beginning of the story.
Here's a checklist I built for myself after one too many 'oops' moments. It covers what I do every time a request for KEMET T530, T495, or even a 'Cypress vs.' comparison comes across my desk—especially when enclosures and 3310 series parts are involved. I call it my 'buying sanity check.'
Who This Checklist Is For (And When to Use It)
This checklist is for you if:
- You're ordering KEMET T530 or T495 polymer capacitors for the first time.
- Someone asked for a 'Cypress vs.' comparison (usually Cypress vs. Infineon or Cypress vs. NXP) and you need to buy the right part.
- ‘Enclosures’ shows up in the BOM, and you're not sure if it's a standard box or something custom.
- You see '3310' on a drawing and aren't sure if it's a connector size, a series number, or a reference.
Use it before you send out the first RFQ. Trust me on this one—it'll save you a return trip to your engineer's desk. There are 5 main steps.
Step 1: Decode the Part Number Before You Search
What to do: Take the part number and break it down into the series, the voltage, the capacitance, and the package.
For KEMET T530 and T495 parts, this is critical. The T530 series is their 'KO-CAP' polymer electrolytic—higher ripple current, lower ESR, better for high-frequency applications. The T495 series is a standard tantalum. They look similar but they're not interchangeable. I assumed 'same specs' once. Didn't verify. Turned out the T495 couldn't handle the inrush current in a power supply circuit. The board didn't fail immediately, but we saw failures at month 4.
Your check point: Confirm with your engineer: Is this a T530 (polymer) or T495 (standard tantalum)? Do they need the polymer? If not, the T495 might be cheaper and fine.
For 3310, I've seen it mean everything from a D-sub connector shell size (DB-31?) to a specific series of enclosures from a supplier like Hammond. In my experience, it's often a manufacturer-specific series number, not a standard. I said 'I'll find a 3310 enclosure' once. They heard 'any box that says 3310 on it.' Result: I ordered something that was 2 inches too small because the drawing referenced an internal shelf depth.
Your check point: Ask for the datasheet or the drawing that references '3310.' Don't assume it's a commodity.
Step 2: Ask the Question 'Cypress vs. What Exactly?'
What to do: When the request includes 'Cypress vs.', stop and clarify the comparison. I get this a lot—someone says 'We need a Cypress MCU' but what they really mean is 'We decided Cypress over NXP after the design review.' The part number is the part number. I've never seen an RFQ succeed based on a generic 'Cypress vs.' comparison without a specific part.
If you're ordering an enclosure or a passive component from a BOM that has a 'Cypress vs.' note, it's usually a design decision that's already made. Don't try to re-buy the decision. Just get the correct part number.
Your check point: Read the full note in the requisition. If it says 'Cypress vs. NXP decision pending,' you can't order that part yet. If it says 'Cypress vs. competitors evaluated, chosen Cypress,' you're good to go—focus on the KEMET components or enclosures.
Step 3: Verify Enclosures Are Not an Afterthought
What to do: When 'enclosures' is on the list, confirm three things: (1) the dimensions, (2) the material, and (3) if it needs custom machining (holes, vents, EMI shielding).
This is where I've seen the biggest price swings. A standard Hammond 1590BB die-cast aluminum box (a 3310-style size) is maybe $15. The same box with a custom-cut front panel and a silk-screened logo? That's $120 plus tooling. I assumed 'enclosure' meant 'buy a box.' Didn't verify. Turned out they needed a custom front-panel with 8 holes for switches and LEDs. The vendor couldn't do it in-house. I lost a week.
Your check point: Is this an off-the-shelf enclosure or a custom job? Get the drawing. Get the material spec. If it's for a KEMET T530 power supply, it might need ventilation or thermal consideration.
Step 4: Calculate Total Cost (Not Just Unit Price)
What to do: When you start comparing KEMET T530 vs. T495 pricing, or comparing enclosure vendors, don't just look at the per-part cost.
I now calculate TCO before comparing any vendor quotes. For a recent order of 1,000 KEMET T530 caps, one vendor had a unit price that was $0.12 cheaper. But they charged $45 for shipping (vs. free from the other), and they required a minimum of 2,000 pieces. The other vendor had a higher unit price but offered free shipping, no minimum, and sent the parts on a reel (which we needed). The $0.12 savings became a $420 headache.
Your check point: Ask for: unit price, shipping, minimum order quantity (MOQ), lead time, and packaging (tape & reel vs. cut tape vs. bulk). If you're buying enclosures, ask if the price includes hardware (screws, standoffs) or if that's extra.
Step 5: Confirm Lead Time Before You Commit
What to do: Lead time is the silent budget killer. For KEMET T530 series, particularly in high-volume packages, I've seen lead times stretch from 8 weeks to 20 weeks in a single quarter. For 3310-enclosures from custom shops, the lead time is often 4-6 weeks if it's a standard color/finish, but 10-12 weeks if it's a custom RAL color.
I assumed '18 weeks is fine' for a T495 part. Didn't verify. Turned out the vendor meant 18 weeks from the date they received the raw materials—not from my order. I had to go to my VP and explain why a $2,400 order was delayed by a month. Looking back, I should have asked 'What is your current lead time for new orders?' and gotten it in writing.
Your check point: Get a written lead time estimate from the vendor. Ask if it's from stock or from factory. Overestimate by 2 weeks for safety. If the timeline is tight, consider a distributor who stocks the parts (like DigiKey or Mouser for KEMET, or a local enclosure fabricator with standard models in inventory).
Common Mistakes I've Made (So You Don't Have To)
Here are the top three traps I've fallen into, in no particular order:
- Assuming 'same specification' means identical performance across vendors. It doesn't. A KEMET T530 cap from one distributor might be a different date code or revision than from another. Ask for the date code and the full part number suffix.
- Not verifying the enclosure dimensions against the board. I ordered a beautiful aluminum enclosure once. It was 0.5 inches too shallow to fit the KEMET T530 capacitors because of their height. The drawing was for a different revision. That was a $600 mistake.
- Assuming 'Cypress vs.' means a price comparison. It usually means a design decision has been made. Don't waste time quoting both. Just get the correct part and move on.
Prices as of February 2025; verify current rates with your distributor. Regulatory info for enclosures (e.g., UL, NEMA ratings) should be confirmed from official sources like UL.com.
