ST attacks MCU dynamic power with 90-nm process, voltage scaling

January 30, 2014 // By Graham Prophet
STM32F4 microcontrollers are the first in what STMicroelectronics is call its STM32 Dynamic Efficiency range; ST says it combines multiple technologies to offer the best balance of dynamic power consumption and execution performance, while boosting feature integration.

The company is using the “ π” logo to convey the concept that it has “squared the circle” and provided greater processing power while reducing overall power consumption.

ST is aiming at markets in portable products, for managing MEMS sensors in smart connected devices, and in Internet-of-Things (IoT) applications and fieldbus-powered industrial equipment, with these ARM Cortex-M4 based, 100DMIPS chips.

ST has balanced the overall power usage of the chips by building them in a relatively conservative 90-nm process to hold down leakage while offering good performance; dynamic voltage scaling adjusts the operating voltage (and therefore, core performance) to meet performance demands, and minimises leakage.

Technologies include a feature called ART Accelerator, a prefetch queue and branch cache. This allows zero-wait-state execution from flash memory for performance of 105 DMIPS (285 CoreMark) at 84 MHz and helps achieve RUN current down to 128 µA/MHz. STOP mode current is 9 µA at 1.8V.

Extending the high-performance STM32 F4 series based on the ARM Cortex-M4 processor with floating-point unit and DSP, the STM32F401 devices integrate up to 512 kByte of flash and 9 kByte SRAM in a 3.06 x 3.06 mm chip-scale package. Peripherals include three 1 Mbit/sec I 2C ports, three USARTs, four SPI ports, two full-duplex I 2S audio interfaces, USB2.0 OTG Full-Speed interface, SDIO interface, 12-bit 2.4Msample/sec 16-channel ADC, and up to 10 timers.

Pricing of the devices is from $2.88 for the STM32F401CDY6 (384 kByte Flash, 96 kByte SRAM, 3.06 x 3.06 mm WLCSP49 package) (at 10,000/yr).