Energy Micro MCU minimizes power consumption in e-paper display solution

April 03, 2012 // By Paul Buckley
Energy Micro has signed an agreement with Pervasive Displays Inc. (PDI) for the use of the EFM32 Gecko MCU to control low power e-paper (EPD) displays.

The deal will enable developers to reduce development time for applications based on the energy friendly EFM32 EPD platform.

Energy Micro’s Taiwan distribution and design partner, Retronix, provided technical and commercial support during the development of a new reference design to support the alliance.

Electronic paper is the lowest power display technology because the devices do not consume energy after they have been updated, however long the image is displayed.  PDI’s e-paper displays, which are ruggedly designed for industrial and commercial applications, reflect light like ordinary paper, making them easy to read in both outdoor and indoor applications. They are currently available in sizes from 1.44-inch to 10.2-inch (37 mm to 260 mm), the largest with a resolution of 1280 x 1024 (160 dpi).

Energy Micro’s EFM32G890F128 Gecko MCU combines ultra-low power and high processing capabilities based on the powerful 32-bit ARM Cortex-M3 processor. The EFM32 MCU was chosen for PDI’s e-paper because it combines low active power of 180 µA/MHz at 3 V with the world’s lowest power standby modes, down to 20 nA at 3 V in shut-off mode, further augmenting the intrinsic low energy consumption characteristics of the display.

Efficient energy modes, a low energy UART and the device’s Peripheral Reflex System make the EFM32 the ideal controller for e-paper applications. The Gecko MCU delivers the processing power needed to refresh the EPD display very quickly. The ‘EPD-On SK2’ reference design uses the standard EFM32 Gecko starter kit (STK) to handle waveform library functions, image transmission via a USB and UART bridge, driving the electrophoretic display’s chip-on-film controller, and displaying the optimized result. The complete reference design from Retronix is powered by USB or a CR2032 coin cell battery.

“Using Energy Micro’s EFM32 Gecko microcontrollers, a single lithium battery cell can power a PDI display for several years in a typical application,” said Andrea Marchi, Energy Micro’s VP Sales and Marketing Asia Pacific. “This is exactly the