Reading data sheets and designing components in DipTrace - Page 1
Forum section: electronics / beginners

author: level42jeff
author_rank: Contributor
timestamp: August 05, 2014, 07:28:54 pm
content: I use DipTrace for my PCB design, as I'm unfamiliar with any other software. I have a new project that I'm working on, (Rather small) and mainly consists of a few chips.One of which is:http://www.spansion.com/Support/Datasheets/AM29F040B_EOL_21445e8.pdfI cannot seem to find this chip in the library of parts, or even something similar, so I've decided to simply build the part myself.I find the dimensions rather hard to follow, and I was wondering if someone could help me understand how to read them. Right now, I'm simply just trying to make the footprint for the part.What I gather is:The pads are 1.2mm x 0.7mmThe spacing between each pad would be 0.22mmThe width of the chip, before the pins, would be 18.50mmAre these the correct measurements, or am I reading this data sheet wrong.---Sorry, I should have specified what my "project" is. I'm trying to make myself one of these:http://www.reinerziegler.de/readplus.htm#Home made carts, however, to avoid the wiring mess, I've decided I'd like to redesign the PCB. I hope this makes sense.Thanks!

author: Bassman59
author_rank: Super Contributor
timestamp: August 05, 2014, 07:32:32 pm
content: Quote from: level42jeff on August 05, 2014, 07:28:54 pmThat device is obsolete and buying them might prove difficult. So consider that before you go through the exercise of creating a component in DipTrace and getting PCBs fabbed.

author: level42jeff
author_rank: Contributor
timestamp: August 05, 2014, 07:36:47 pm
content: Quote from: Bassman59 on August 05, 2014, 07:32:32 pmIs there a modern day equivalent you could point me in the direction of?Also, added some additional details about my "Project" to the first thread. Hopefully this makes things clear.

author: miguelvp
author_rank: Super Contributor
timestamp: August 06, 2014, 03:44:48 am
content: Haven't tried octopart search, but findchips shows a lot of stockhttp://www.findchips.com/search/Am29F040B

author: level42jeff
author_rank: Contributor
timestamp: August 06, 2014, 01:31:00 pm
content: Quote from: miguelvp on August 06, 2014, 03:44:48 amThanks for the tip!, I have a small side question for you guys, hopefully this will be easy to answer, but what do the last 4-5 digits in the part number mean?Example, the results from findchips.com yeilds many "variations" on the chip I'm after. What do the characters inboldmean?AM29F040B-70JFAM29F040B-90JFTAM29F040B-90JIAM29F040B-90EFAM29F040B-70JITAM29F040B-55JF\TAM29F040B-55EF---Also, still looking for some guidance on the chip measurements. Thanks!

author: miguelvp
author_rank: Super Contributor
timestamp: August 06, 2014, 01:57:34 pm
content: On that list you select one of the (for example Arrow) and it has the datasheet includedOn page 5 of the pdf file it will tell you that is the speed, package type and temperature range codes. details in the datasheet.

author: level42jeff
author_rank: Contributor
timestamp: August 06, 2014, 02:12:55 pm
content: Quote from: miguelvp on August 06, 2014, 01:57:34 pmIs that what the last few digits mean?---[Edit 1]Found this in the Data Sheet:This is what I'm looking for right?

author: Dongulus
author_rank: Regular Contributor
timestamp: August 06, 2014, 04:00:54 pm
content: Coincidentally, I just last night submitted my gerber files to OSH park for a PCB I designed to replace a Super Nintendo cartridge mask ROM with a re-programmable flash chip. The first hurtle I ran into was finding a suitable flash chip that could run on 5V for a not absurd price. The memory depth I was looking for, 32 Mbit, yielded no results on Digikey, Mouser, nor Avnet. I eventually found an old Intel flash chip that suited my needs atthis website.But, you are looking for a 4 Mbit (512k x 8bit) flash chip. It seems like you still have some options with the big distributors. Here is a Digikey parametric search I did for a 5V, 4-8 Mbit flash chip in a SOP package.Here are the cheapest options at a quantity of 1:Macronix MX29F400 $1.88 USDMicrochip SST39SF040 $2.03 USDYou might have better luck finding older chips for sale on eBay or elsewhere that the seller wants to get rid of, like in my case.Another thought, how have you planned on programming your chip? I don't have a universal programmer, so I planned on building a programmer from one of my TI launchpads. Interfacing the 5V TTL with 3.3V logic might prove tricky though.

author: level42jeff
author_rank: Contributor
timestamp: August 06, 2014, 04:11:29 pm
content: Quote from: Dongulus on August 06, 2014, 04:00:54 pmActually, I've got several of the Commercial programming systems, I was really hoping to use one of these to dump my ROM file. I've been checking on ebay for the AMD flash memory chips, but I'm not confident enough to start venturing off the tutorial in finding other parts.

author: Dongulus
author_rank: Regular Contributor
timestamp: August 06, 2014, 05:03:52 pm
content: Quote from: level42jeff on August 06, 2014, 04:11:29 pmAh, I understand. In answer to your original question, your dimensions are off. A TSOP pad is 0.2mm wide by 0.8 mm long, nominal. The pitch between pins is 0.5 mm nominal from their center lines. The width of the chip is 18.4 mm.The drawings in this datasheet are a little confusing. It's not at all obvious, but the drawing labeled "Section B-B" appears to be a cross section of one of the pins. Dimension 'b'/'b1' is the width of the lead. The pin length is one half the difference between dimension 'D' and dimension 'D1'. Dimension 'e' is the pin pitch. See page 3-1 ofthis documentfor clearer drawings and descriptions of TSOP dimensions.