Tag Archives: analog aficionado

All tiny AVR parts in a spreadsheet

I just made a spreadsheet of all the tinyAVR parts. All my pals love the MCU selector guide, but I have a lot of analog dinosaur buddies that prefer a spreadsheet to a web-based interface. You can sort the data and this spreadsheet has the filter box on the columns, so you can sort out things you care about and exclude the things you don’t. The spreadsheet fits on a 24-inch display, and you can print it out on a single B-sized sheet and use it as an infographic.


This screenshot shows how all the tinyAVR parts will fit on one 11×17 ledger-sized or B-sized sheet of paper.

I started with an Excel dump of the selector guide after adding every single parameter to the search. I then took all the tinyAVR parts, and rearranged the columns, throwing out the irrelevant ones. I also combined the automotive parts with the basic parts. That added two columns for automotive temp and automotive Vcc range. Adding 2 columns to remove 13 rows seemed like a good deal. The part name links to the product page on our website.

I made a column for each package. That took a long time. Semiconductor companies think of a part as the silicon die, with the package being almost irrelevant. We systems folk know the package might be the most important thing. I tried to put the smaller packages on the left, with those big ol’ DIP (dual-inline plastic) parts on the right side. There is a second sheet in the spreadsheet that shows all the parts by number and there I put the package size, in mm. In both sheets, the package name links to the definition page on our website.


The second sheet of the spreadsheet shows all the tinyAVR parts by number. I put the exact package size on this page.

Besides the packages and package size, I also spent a long time getting pricing. My buddy Wayne Yamaguchi requested this, and he is absolutely right, price is the most important spec of any part, and I hate when it takes 5 clicks to find it. These prices are a bit sketchy. All I did was click on the “Buy” link and select a handful of parts from each family, and then looked at the Digi-Key price, in 1000s. I put in the highest and lowest of the few I selected, but this is by no means scientific or dispositive, as the lawyers would say. What I should do is put the price in the “Package” column, so you know what the package is and what price we charge, but many parts are in the same package but have two Vcc ranges, so there is no unique way to encode this and keep the spreadsheet on one printable page. Maybe I can blow out the second page to show every orderable part number and its price and specs. Always time to do it over, never time to do it right.

The major thing I want to add is the OrCAD 9.2 footprint name for the packages. I am afraid to do this now, since we have all been burned by narrow-DIP/wide-DIP and narrow -SOIC/wide-SOIC and what pin numbering to use on SOT parts, so that will have to wait for next time. If anyone has a proven definitive list of the OrCAD footprints, please let me know. paul.rako[yeah, the at sign]atmel.com

You can highlight all the parts and use the “Data>Sort” function to order them any way you want. I did it by Flash memory size and part name. You can also use the little filter boxes on each column to include or exclude, or even put in a logical range with equal or less than or all the other things. Its not exactly grep or regular expressions, but it can get the job done helping you to find the right part.


Excel filter boxes let you select just the parameters you care about.

I am told this spreadsheet works OK in Open Office/Libre. My pal Dave asked that any columns that are filtered be lit up red, but that takes a macro, and the VB macro may not work in Open Office, we are checking for that. Meanwhile, check there are 36 part families or that the little filter box does not have 3 pixels different to show the filter is on.


When you have filtered a column, it is almost impossible to tell, since the only indication is the icon makes this 3-pixel change.

Weasel weasel, CYA CYA, legal boilerplate—this is a hobby job, not an official Atmel document. If the selector guide had it wrong, it is wrong here too. I made my own mistakes too. And I already told you the pricing and the tiny1634 stuff was dicey. What I am hoping is that I can get some community support where you point out the errors, and tell me what to add. paul.rako[yeah, the at sign]atmel.com I also ask that you send this URL link to your pals, instead of just emailing the spreadsheet. That way the bosses will see you like this, and I can have the time to keep working on it.


If Hans Camenzind, the inventor of the 555 timer chip was still alive, he might have a copy of the tinyAVR spreadsheet up on his office wall. I miss Hans, at least he came to my Analog Aficionados party one year, before we lost him to the Grim Reaper.


Video: PCB 201 with Atmel’s Paul Rako

In this Atmel Edge episode, Analog Aficionado Paul Rako demonstrates how to place a switching power supply on the same circuit board with analog and digital circuits.

“It’s a fairly high-level clever trick to lay out a switching power supply on a board that has analog and digital and some delicate circuits,” Rako explains.

“What did my two friends – Jon Dutra and Alan Martin – come up with? You use a top-side copper pour on your circuit board to make a local ground for your switching regulator. And then you just connect it at one place, at the bottom, at the ground reference of the output capacitor.”

To illustrate his point, Rako highlights a four-layer circuit board.

“So this is top, signal, then there’s ground, then there’s power plane, then there’s bottom signal. Design it four-layer. When you get that figured out, then you can spin it down to a two layer. A buck regulator, has an input voltage. Got an input capacitor. Then you’ve got a switch,” he continues.

“Usually it a FET transistor, or sometimes it’s inside the control IC. Here’s that control IC. Then you’ve got a catch diode, which causes a lot of problems. It gets hot. Sometimes it’s inside the IC. Sometimes it’s a synchronous. The basic thing with a switching regulator is this inductor. Then you’ve got an output capacitor. And always put those arrows and feathers on your circuit so people understand what’s coming in and what’s going out.”

As Rako notes, the inherent problem with a switching regulator is its fast-changing currents, di/dt.

“Those fast-changing create electromagnetic noise. If you let them run in the ground plane they’ll go out and affect other circuits on your PCB. So the trick is you pour a top-side copper pour,” he added.

Interested in learning more? Be sure to watch the video above for a full PCB 201 run-down.

Video: Schematic 101 with Atmel’s Paul Rako

In this episode of Atmel Edge, Analog Aficionado Paul Rako discusses the importance of understanding ground symbols for electronic schematics. As Rako notes, Earth ground, chassis ground, power supply return and shield are all different. This video explains why.

“Earth ground has a very precise meaning and a very precise name, and it’s earth ground. My professor, James T. McLaughlin, at Kettering University previously General Motors Institute, pointed out [that] earth ground is a ten foot copper-clad steel rod,” says Rako.

“And you hammer it into the dirt. And you make sure there’s moisture so it has conductivity. The minute you hook a wire to it, well now you got some inductance. And 12-gauge wire all the way to get to where earth ground has to get, which is this third pin on your wall socket, well now it’s got a little resistance, as well.”

Rako also points out that a car isn’t grounded.

“What you want to use is this symbol, which is chassis common. And chassis common, it’s not just cars, but television, radios, PCs with metal things. Anywhere there’s a metal case or a metal mounting point, that’s chassis common. In America, if a human being can touch that metal, you have to connect earth ground at chassis common,” he notes.

“Underwriter’s Laboratory requires a ring terminal so it doesn’t get pulled off. And that way, if there’s a short of high voltage on to the chassis — a wire or something falls down — then it can seek a ground through this earth ground and trip a circuit breaker instead of electrocuting your customers.”

As Rako emphasizes, semiconductor companies who make chips should be using this symbol, the triangle.

“That is power supply return. You may connect your circuit board in the corners, it may connect to chassis, and maybe you want that,” he adds.

“Maybe you want it to connect at 100 places to get a really good RF connection between the circuit board and the metal chassis. But this symbol would be improper on a circuit board, and certainly earth ground is wrong.”

You can watch the video above for more information about schematics. Readers may also want to check out Rako’s previous Debug 101 episode here.

Video: Debug 101 with Atmel’s Paul Rako

In the first installment of this series, analog aficionado Paul Rako offers viewers an overview of Atmel debuggers such as the $49 AVR Dragon, JTAGICE3 and AVR ONE.

“For $49, you can get a debugger that’ll let you watch the chip execute, let you single-step through your program, let you see the effect of interrupts, and can really speed up how fast you’re bringing your program or your product, and the program in it, into market,” said Rako.

“Next up is [the $100] JTAGICE3. In addition to doing all the AVR chips and the AVR 32-bit chips, this product will also do the SAM D20 ARM Cortex M0+ chip. [There is also] the JTAGICE2. We used to sell this for $400. I’m kinda proud that we reduced the price by one fourth for the subsequent product.”

Meanwhile, Atmel’s AVR One! offers trace capability.

“With trace, you let your program execute. The trace just records. It’s like a log file and it tells you what’s going on. So, it’s $600. It’s hard to do trace real-time at the kind of speeds our microcontrollers (MCUs) run.”

As you can see in the video above, Paul also gets up close and personal with Atmel’s ARM-based SAM D20 Xplained Pro.

“What’s cool about the SAM D20, it’s an eval board with the chip, but it’s also got the debugger chip. You can come off of this board – when you get along with your design, you design your own PCB you can jump off of this board,” Rako explained.“And instead of debugging the SAM D20 that’s on this board, it’ll debug the SAM D20 that’s on your printed circuit board for your system.”

Last up is Atmel’s Cortex 4 Xplained.

“This isn’t an Xplained Pro- but because it’s the 4S, it just happens to have a debugger on it as well. You can use our STK600 and one of these debuggers to program and debug the things. You can use an Xplained Pro card,” Rako added. You can use some of the Xplained boards that have a debugger on them. It’s going to be so much faster than trying to write – printf – do a little flag, and write some thing off the serial port, to try to figure out where your program’s going, why it’s not doing what you expect.”