I'm designing a USB-powered microcontroller board, and I'm considering choosing a Cortex-M7-based microcontroller for it (I want a double-precision FPU, along with other features M7 offers). Currently, there are 2 MCU families commercially available:
- STMicroelectronics STM32F7,
- Atmel SAM S70 / E70 / V70.
Because my board will only be powered by USB cable (through Type-C connector / USB 3.1 PD chip), I thought of choosing a MCU based on their power consumption - but I couldn't find any numbers.
STM manufactures it's MCUs using pretty aged 90 nm process; Atmel doesn't disclose any manufacturing details, but collective consciousness of the Internet says it's 55 nm process - thus it should be more power-efficient.
Are there any figures/estimates publicly available on the power consumption of the above MCUs? Any measurements of yours?
I totally understand that there are different usage scenarios possible; also, each MCU comes in a variety of variants among which power drain may vary. I'm not looking for comparisons, but rather for various measurements or different chips, which will help me estimate.
Thank you in advance.