Consuming just one-third the power of comparable products in the market today, the new ultra-low-power Atmel® SAM L21 family expands the Atmel® | SMART 32-bit ARM®-based products using patented Atmel picoPower® technology.
The SAM L21 family delivers ultra-low power—down to 35µA/MHz in Active mode running EEMBC CoreMark, sub 900nA with full SRAM retention and RTC, and 200nA in the deepest Sleep mode. With an ARM Cortex®-M0+ CPU, rapid wake-up times, Event System, Sleepwalking and innovative picoPower peripherals that can remain running while the rest of the device is sleeping, the SAM L21 family is ideal for handheld and battery-operated devices in a variety of markets, including IoT, consumer, industrial and portable medical applications. The new SAM L21 devices also feature an improved low-power PTC that enables wake-up from touch down to 2.5uA.
With over 50 billion devices predicted for the IoT market by 2020, there is a need for lower-power microcontrollers (MCUs) that will drive these applications without adding load to power grids or requiring frequent battery changes. This latest Atmel MCU family is designed precisely for these applications, expanding battery life from years to decades.
The SAM L21 is the world’s lowest-power ARM Cortex-M0+ based family of devices, expanding Atmels product offering beyond the SAM D family to address the next generation of ultra-low-power products. This new Atmel new family also integrates additional functionality like Full Speed crystal-less USB, low-power peripheral touch controller that requires no external components, Event System with second-generation sleepwalking that gates both clock and power, low-power 12-bit 1Msps ADC, 12-bit DAC, DMA, timers/counters for control applications, 3x internal opAmps, programmable custom logic, and several other new features. Atmel | SMART cortex-M0+ devices from the SAM D10 to the SAM L21 are code- and pin-compatible, making it easy for designers to migrate up and down the family.
As seen from the competitive analysis below, no current solutions come close to the Atmel | SMART SAM L21 devices in Active mode. The devices that have similar current consumption values for the deep Sleep modes neither have the SRAM and Flash sizes nor the processor speed needed to run an IoT application with a wireless stack.
Device |
SAM L21
|
Freescale
|
Freescale
|
ST
|
SiLabs/ EM
|
|---|---|---|---|---|---|
CPU |
CM0+
|
CM0+
|
CM0+
|
CM0+
|
CM0+
|
Flash |
64K-256K |
32K–256KB |
8–32K |
32K-64KB |
4K-32KB |
SRAM |
8-32K |
4 – 32KB |
1 – 4KB |
8KB |
2 – 4KB |
Supply voltage |
1.62-3.6V |
1.71-3.6V |
1.71-3.6V |
1.65-3.6V |
1.8-3.6V |
Event System / DMA |
16-ch / 16-ch |
Some functionality / 4-ch |
Some functionality / 0-4-ch |
– / 7-ch |
4-ch / – |
USB |
FS host/device |
FS host/device |
– |
FS device |
– |
ADC |
12-bit
|
16/12-bit
|
12-bit
|
12-bit
|
12-bit
|
ADC gain stage |
Using Op-amp |
– |
– |
– |
– |
DAC |
12-bit
|
12-bit |
12-bit |
12-bit |
– |
Op-amps |
3 |
– |
– |
– |
– |
HW touch |
Yes, best performance |
Yes |
Yes |
– |
– |
Active current @ 3V
|
35 µA/MHz |
135 µA/MHz |
120 µA/MHz
|
150 μA/MHz (4MHz) |
140 µA/MHz
|
SRAM retention + RTC @ 25°C |
0.9 |
1.7 |
1.7 |
0.8 |
0.9 |
Wakeup time from SRAM retention mode |
4 µs |
10 µs |
4 µs |
5 µs |
2µs |
Int RC drift (-40+85°C ) |
<+/- 1% |
+/-3% |
+/-3% |
-2.5/+2% |
+/-3% |
Active mode current consumption on microcontrollers is highly dependent on what type of code is executed by the processor. The table above shows how the Atmel SAM L21 family compares to our competitors running the Coremark algorithm, one of the most power-intensive algorithms to run, putting heavy loads on not only the CPU and SRAM but also the Bus matrix and Flash.
