Introducing the world’s most innovative 2-pin, self-powered Serial EEPROM

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Atmel has launched the industry’s most innovative Single-Wire EEPROM with only two-pins, making it ideal for the Internet of Things, wearables, consumable, battery and cable identification markets.

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The advent of smart gadgets has increasingly made it necessary for embedded systems to store small amounts of information about the system itself. While a majority of memory technology development has been dedicated to increased capacity at low costs, a new class of memory applications have arisen that demand only modest amounts of memory. However, because these memories provide capabilities that might be considered administrative or overhead, space and power must be kept down to an absolute minimum in order to keep the extra functionality from pushing the system beyond its power and size requirements.

Fortunately, a new class of serial EEPROM has emerged to satisfy this need. Meet the Atmel AT21CS01/11 SEEPROM. Tapping into our legacy of delivering “advanced technology for memory and logic,” hence our name, Atmel has launched the industry’s most innovative Single-Wire EEPROM with only two-pins — a data pin and ground pin for operation — making the new family ideal for the Internet of Things, wearables, consumable, battery and cable identification markets.

The AT21CS01/11 are self-powered, eliminating the need for a power source or Vcc pin, with a parasitic power scheme over the data pin. This latest set of devices provide best-in-class ultra-low power standby of 700nA, 200µA for write current, and 80µA for read current at 25 degree Celsius—delivering just one-third of the power of leading competitors.

With confined spacing in smaller IoT, wearables, battery and cable identification applications, the AT21CS01/11 eradicate the need for external capacitors and rectifiers with its parasitic power scheme over a single data pin. Additionally, the new devices have an ultra-high write endurance capability to allow more than one million cycles for each memory location to meet the requirements for today’s high-write endurance applications.

The AT21CS01/11 products include a simple product identification with a plug-and-play 64-bit unique serial number in every device, making it ideal for connected gadgetry in today’s IoT world. The new Single-Wire EEPROM family also delivers industry-leading electrostatic discharge (ESD) rating (IEC 61000-4-2 Level 4 ESD Compliant), so applications such as cables and consumables can tolerate exposure to the outside environment or direct human contact while still delivering flawless performance.

“With Atmel’s legacy rooted in memory, we are excited to bring a new generation of innovative ‘true 2-pin’ serial EEPROMs that are parasitically powered,” explained Padam Singh, Atmel’s Director of Marketing, Memory Products. “Our new Single-Wire EEPROM family makes it very convenient to add serial EEPROM using just one-pin from the MCU/MPU without the need to route the Vcc to the device, delivering significant board space savings while simplifying the layout. In addition, the plug-and-play 64-bit serial number is the easiest way to add identification to various accessories and consumables. We look forward to proliferating these products to next-generation applications and delivering more value-added solutions and industry-firsts.”

The recently-revealed products follow the I2C protocol, allowing for an easy migration from existing EEPROM with less overhead and capability to connect up to eight devices on the same bus. The AT21CS01 offers a security register with a 64-bit factory programmed serial number and an extra 16-bytes of user programmable and permanently lockable storage, delivering a guaranteed unique serial number for inventory tracking, asset tagging and can permanently protect the data if needed.

There are two variants of the device available to support different voltage requirements. The AT21CS01 is targeted for low-voltage applications operating at 1.7V-3.6V. For applications that require higher voltage ranges such as Li-Ion/polymer batteries, the AT21CS11 will support 2.7V-4.5V operating range and is the ideal product to meet IEEE1725 specifications for electronic identification of battery packs.

Interested? The AT21CS01 is now available in production quantities in 3-lead SOT23, 8-lead SOIC and 4-ball WLCSP, while the AT21CS11 will debut later this year in Q4. Read more about the 2-pin, self-powered Serial EEPROM series here.

When it comes to firmware, when in doubt don’t leave it out!

Product design teams endeavor to plan the safe launch of electronics products to prevent re-discovering issues that should have been learned from the previous project. Many Serial Electrically Erasable Programmable Read-Only Memory (SEEPROM) users have never utilized such components and therefore may not have knowledge of potential issues. Here is a personal story from several years ago when I was asked to support a customer working on an issue on a weekend. (You may have already guessed that the call came to me that weekend was from my boss’s boss’s boss.)

Here’s the issue that was described to me over the phone by the customer engineers (hardware and firmware) while they were in their laboratory troubleshooting:

We exchanged emails with DSO (digital storage oscilloscope) captures of the serial protocol after which I would request another DSO capture or two. Once we were drilling down to the issue, a customer firmware engineer held the phone line while the customer hardware engineers made more measurements. The customer firmware engineer asked me, “Why would someone drive the SEEPROM /CS signal low (true) and then back high (false) with no clocks or data in?”  I quickly whipped out, “That is a chip select toggle that is utilized to recover from power interruption of the host microcontroller or from a protocol violation, and we have a Juraasic period FAQ about that buried deep in our website.”  The customer firmware engineer said, “Uh oh, I didn’t know why anyone would do that, so I took it out.” Soon, the hardware engineers emailed me a DSO capture showing a protocol violation and then no communication from the SEEPROM. I announced that the firmware engineer has the solution to this issue and should be able to produce a new firmware build to mitigate this situation in the future.

Several product lines were brought to a standstill because the task to reduce firmware lines of code took precedence over why the code was there to begin with. Numerous engineers (including myself) have worked weekends unnecessarily. The moral to the story is that if you have product firmware that communicates properly with an Atmel SEEPROM and you do not know why a few lines of code exist, then you may want to ask yourself about the expected benefit of modifying that code before you throw the baby out with the bath water. Sometimes things are there for a reason that may not be all that obvious.

Stick to the adage: “When in doubt, don’t leave it out.”

Oh, and one more thing… Please comment your firmware source files adequately to help the next firmware developer. Remember that person may just end up being a future version of you!

This blog was written by Clay Tomlinson, Atmel Staff Applications Engineer