What is the (theoretical) power requirement for different micro controllers to during deep
sleep and to generate a PWM signal and measure voltages?
Numbers are taken from the respective datasheets. PWM currents do not include
driving the output pins.
ATtiny85 (1.8V)
- power down:
- watchdog on: 3uA
- watchdog off: 300nA
- idle (hence able to maintain PWM, and run ADC):
- 1.8V 1MHz: 90uA + 5uA (pwm) + 15uA (adc) = 110uA
- 1.8V 4MHz: 200uA + 30uA (pwm) + 85uA (adc) = 315uA
ATmega328p (1.8V)
- power down:
- watchdog on: 3.5uA
- watchdog off: 100nA
- idle (hence able to maintain PWM, and run ADC):
- 1.8V 1MHz: 100uA + 22uA (adc) + 20uA (pwm)
- 1.8V 4MHz: 400uA + 90uA (adc) + 80uA (pwm)
STM32L431
(1.8V)
- power down (absolute lowest, standby has similar stats but faster wakeup):
- stop 2 mode (can run pwm via low power timer - not 100% sure this lets you run
a high speed PWM)
- 1.8V 1.4uA w RTC + 1uA/MHz (lptim1) + 2uA/MHz (gpio)
The STM32 looks very promising as a low power microcontroller which can still
pack a punch when needed (by going up to 80MHz and drawing a few mA).