REV9 evaluation and testing, hardware just arrived

Development
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  • LMV321 (U404, U603) was GS6001
  • LMV321A (U601) was GS6001
  • LMV331 (U602) was RunIC part
  • 74HC4067 to CD4067 (I core)
  • All 74xx logic to I core
  • pullup system to SI2301 pfets (remove 2 x 74hc4066)
  • WST pfets to si2301 SOT-532 (brand, size change)
  • 1n4148 to do 523 (size change)

Sorry this took so long. We put one through two weeks ago, tested it, and it failed miserably. I changed the op-amps and didn’t realize the footprint was different. A ‘Y’ version of the lmv321 is in the datasheet that matches the gs6001, but it’s not widely available and I just didn’t notice it was special order.

We ran a second one just before the office went on holiday last week. It did pass the self test and UPS just dropped it off to me. I’ll open it and post some pictures when I finish my current task.

As an aside: I just love saying Wuxi I-core, great name! (wooshe i core!)

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REV9 vs REV8.

  • You can see some FETs and the diodes are much smaller SOT-523 packages.
  • I also standardized on the si2301 as the PFET of choice (I think we’re using CB2301(2.8A)).
  • The two 74hc4066 chips are gone in favor of pfets as high side switches.
  • The analog changes you can’t really see, except for a few rotated op-amps due to the new pinout
  • Updated the 0402x4 R array footprint paste layer because we’ve had more stuck pins that I’d like.
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Tests:

  • op-amp ADC buffer: perfect
  • op-amp voltage set: perfect
  • op-amp current sense: ok, if somewhat improved from the GS6001 (used an ‘A’ spec lmv321). I still have a feeling someone is going to come along and tell me all the terrible mistakes I made in the iSense stuff.
  • comparator: perfect. Tested current limit response at 40, 100, 140 mA
  • CD4067 response time: the I-CORE CD4067 has better specs on paper than the Nexperia 74HC4067, at a fraction of the cost. I wasn’t sure about this one, but it really does have better switching times and there is no bleed through of voltage measurements at higher speeds anymore.
  • pullups: Looks great, and even works at low voltages with no issues.
  • buffers: I had a scare, after pullups were turned off they floated around 2.3v. Touch it with a multimeter and it goes back to 0. I though, well, we may have gotten the bus hold version. I took it out of the case and looked under the microscope, nope, right part code. Put it back in the test rigging and tried again. No problem, works perfectly. What was it? The bus hold in the logic analyzer :smiley:

REV9 is ready for FCC and CE testing on Monday.

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Hi Ian

Is there any news regarding the availability of the REV9 to purchase it?
I have a friend who is waiting and was asking me for information.

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It’s going to be 2-3 weeks unfortunately. I had to make a few very last minute revisions, but the overall design is much more robust.

We’ll have engineering samples of REV10 next week. It will take me a day to evaluate and then we’ll send it for FCC testing (1 week). After that about 3 days for production PCBs and 24 hours to get them assembled.

The other hold up is that we still don’t have the case. It should have been done this week, but I haven’t heard anything from the factory yet.

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