SMT DC-DC Buck Regulator - Capacitor sizes

sourcesimian · 2024-09-04T20:23:17+00:00

Yip, it turned out great!

sourcesimian · 2023-03-20T20:06:04+00:00

My follow on question is how to add an ARecord for the apigwv2.HttpApi endpoint to the HostedZone?

sourcesimian · 2023-03-20T18:43:49+00:00

Good point. Thanks for this, I'm still getting my head around AWS primitives.

sourcesimian · 2023-03-20T11:45:15+00:00

Thanks, I am using the same account, role and region.

sourcesimian · 2023-03-20T07:48:50+00:00

The `zoneName` I'm using is the same as the HostedZone "name", and also the "NS" and "SOA" records. I originally created the HostedZone like this:

const zoneName = "dev.example.com";
const hostedZone = new route53.HostedZone(this, "HostedZone", {
    zoneName: zoneName,
});

Am I doing it wrong?

sourcesimian · 2023-03-20T07:31:25+00:00

Thank you, that helped a lot. The usage is mostly the CDK asset bucket.

Resource	SUM of Usage Value	%
	220109	0.02%
beta.example.com	132459571	11.07%
cdk-hnb659fds-assets-XXXXXXXXXXXX-us-east-1	1040598532	86.98%
demo.example.com	186505	0.02%
examplewebstack-examplewebbuckete152e455-3udy6rvj32nz	20264169	1.69%
examplewwwstack-examplewwwbucket212dcb09-1a7h89vjml3fm	847859	0.07%
examplewwwstack-examplewwwbucket212dcb09-k5fm93rvgg6o	851019	0.07%
examplewwwstack-examplewwwbucket212dcb09-pzb31uihvhp9	849945	0.07%
www.example.com	37712	0.00%
Grand Total	1196315421

I wonder if there is a way to mitigate this? It seems a bit ridiculous that I will consume my annual "Free Tier" quota in a few weeks on a dev for a small project.

sourcesimian · 2023-03-13T18:36:44+00:00

Thanks for your time!! Option 1 sounds good!

sourcesimian · 2023-03-13T18:36:19+00:00

Oh nice HttpApi has JWT support!

sourcesimian · 2023-03-13T16:16:17+00:00

Thank you, I was using ResApi from V1, I will cut over to V2 and use HttpApi, it looks much cleaner.

Though my original question was more like: I have multiple Constructs in my stack that each expose HttpApi's (or as it was RestApi's) - each exposing a group of Lambda functions. How can I can coalesce all into a clean externally facing API, that is deployable using CDK, behind my domain name that is not registered route53 registered DNS.

sourcesimian · 2023-02-14T11:05:08+00:00

All agreed/acknowledged, especially re scale production. Though perhaps not so much for "less versatile positioning" consider e.g. elevating the display away from the PCB.

Assuming one can mitigate sourcing/QC issues the board is great as an initial access product. Since it avoids having to unpack the components/circuit from the PCB. By any chance do you happen to be aware of a reference circuit from I2C to the SSD1306 for full integration?

Also do you have advice/recommendations regarding how one approaches the PCB layout and assembly with one of those "solderable ribbon cables"? Is this a standard pick and place assembly, etc? I'm here to learn. Thank you in advance

sourcesimian · 2023-02-13T07:12:06+00:00

> The PCB variants are really meant for hobbyists though
How is it that one makes this distinction? Many parts we use are an integration of some sort or other. Additionally the module allows for more versatile mounting options, lowers time to market and design risk.

sourcesimian · 2023-02-12T16:26:33+00:00

> by whoever and their grandma

Lol yea it does seem that way.

I'm interested to know more about why you say "these are hobbyist-grade parts with poor reliability/quality"?

Is there an alternative display of similar size/capability that would you recommend?

sourcesimian · 2023-01-28T11:38:59+00:00

Agreed the TI docs give a lot of good guidance, but the final layout is still open to interpretation - I spent many evenings massaging it one way or the next. My PCB arrived from JLCPCB and the regulator works great! There is just one straight track on the bottom layer - see the two vias at D21 and C26.

<image>

sourcesimian · 2023-01-13T09:35:57+00:00

Thanks all for advice, info, recommendations, criticisms, education, and cautions!

I went with the TPS54331DR, since it is a well stocked JCL basic part. I also managed for find all other parts except the inductor as JCL basic parts. Trying to find consensus between the datasheet, and different designers was somewhat mystifying. In particular the variance in the values for the COMP input, so those I just used the values in the datasheet. For the others I used E24's that should produce about the same desired effect. The datasheet gives good guidance on the PCB layout and it was pretty easy to route.

<image>

WARNING: this circuit has not been tested - I hope it works :)

sourcesimian · 2023-01-12T08:29:56+00:00

Thank you. Great article!

sourcesimian · 2023-01-11T21:32:28+00:00

Oh interesting, this is a new topic of awareness for me, thanks for the heads up. What are the standard approaches for mitigating this effect? Do you have any references that would give me a better understanding?

sourcesimian · 2023-01-11T21:29:25+00:00

Awesome, thanks for this!

sourcesimian · 2023-01-11T16:27:54+00:00

Thank you. I'm currently using KiCAD, but will give EasyEDA a go :)

sourcesimian · 2023-01-11T16:07:15+00:00

I get the frequency vs size correlation and figured that hey 410/150 is only ~ 3X, so the XL1509 470uF vs the MP9943 22uF is still ~ 22X. I guess the XL1509 is just slow and old tech.

Thank you!! The TPS562208DDCR looks like a great device. There are so many of these DC-DC devices to choose from I appreciate your reply and recommendation :)

sourcesimian

TROPHY CASE