Lowest current Arduino

Using Arduino General Electronics
#1

I have at the moment a circuit using an Atmega328P that sleeps using the timer and consumes ~4.5uA in sleep mode. Is there any way to get that lower? Is there other Arduino based chips that can sleep with a wake up timer better than an Atmega328P?

Its in 3.3v 8Mhz mode.

Thanks!

FYI I read everything from Gammon already ;)

#2

Why not read some datasheets of the other atmel chips?

#3

Because sometimes there is some else on the forums who has already done some amount of grunt work. Not all Atmel chips are Arduino compatible as well.

#4

You should be able to get it a little lower than that. What do you have for the circuit?

Have you read Nick Gammon's power usage guide?

#5

I have, the extra 1uA is from a sleeping xBee transmitter.

I see these bluetooth modules that can sleep and function under 1uA and I hope to get something closer :)

#6

Attiny 24-44-84, 0.13uA in sleep mode and WDT disabled and VCC = 3V. Attiny25, similar. Attiny2313, similar. Atmega1284P, similar, 0.15uA. WDT enabled, 5uA. In sleep mode with WDT disabled, nothing is switching internally, so no power is consumed.

#7

So basically the numbers I am getting with a WDT enabled is about right across the board ?

Is there a way to use the 32Khz Osc instead in sleep mode?

#8

If things are switching, you’re not going to get lower.

#9

Power in a digital CMOS chip is proportional to clock frequency, how many gates are clocking(*), and supply voltage squared. (plus some losses from the crystal oscillator and analog circuitry in practice)

Thus the 3.3V 8MHz ATmega running normally consumes less than a quarter of the power as at 16MHz and 5V...

(*) actually the total capacitance of all signals / gates that are clocking, thus f C V^2

By the way trying to get the current consumption below a few uA may be fairly pointless - the leakage current in your battery will start to dominate at some point, so you may be making no further improvements to battery life. 5 years at 5uA is 220mAh of charge (pretty small battery), yet some battery technologies self-discharge on faster timescales than this.

#10