Flash MCU ups impedance matching at low power

Atmel Corp. has launched the SAM3S series of 18 general-purpose Cortex-M3 based flash microcontrollers that improve impedance matching, simplify PCB design and save 50 percent power at 1MHz operation with a consumption of only 2.3mW. At maximum operating frequency of 64MHz the device consumes 1.45mW/MHz.

Inspired by the ARM7TDMI-based SAM7S series, these MCUs enable SAM7S customers to migrate to a 50 percent more powerful and feature-rich MCU, while preserving hardware and software investments. Atmel's SAM3S also expands market opportunities in applications including consumer, industrial control, metering, toys, medical, test and measurement, 802.15.4 wireless networking, PC, cellphone and gaming peripherals.

The SAM3S is a member of Atmel's Flash MCU family based on the high-performance 32bit ARM Cortex-M3 RISC processor. It provides processing power and features such as system control, sensor interfaces, 64k to 256Kbyte flash memory options, an optional external parallel bus interface, connectivity capabilities and user interface support. Additional features include On-Die Termination (ODT), USB Device, SDIO, Parallel PIO signal capture, 12bit ADC and DAC, 4 UARTs, dual I?C, I?S, timers, unique chip ID, and power and reset management. The SAM3S锟絪 supply voltage ranges from 1.62 to 3.6V operation and package options from 48-pin QFP and QFN up to 100-pin QFP and BGA.

Integrated resistors
Termination resistors are conventionally added externally to improve impedance matching in transmission lines and avoid signal reflection which can result in erroneous data transmission and current peaks degrading the EMI behavior of the system. ODT consists of integrating the termination resistor inside a semiconductor chip instead of on a PCB. The SAM3S has integrated series resistors on the outputs with a typical value of 35?, which result in a reduced BOM cost, real estate savings and facilitate PCB design.

Power optimization at reduced operating frequency—Atmel has taken the following steps to minimize the dynamic power consumption of the SAM3U devices in operating modes up to 10MHz reaching an estimated power consumption reduction at 1MHz of 50 percent:

??Extended supply range from 1.62V to 3V

??Sense amplifiers of the Flash memory are automatically put to sleep after completion of the read cycle

??The Flash memory can be read in x64 mode instead of x128 without compromising performance

??A self-adapting regulator scales current consumption as a function of current draw without any software handling

1???2???3??