xMega power consupmtion

[Aleksandar B.]

I have a project where one of the requirements is for the device to be battery powered. The electronics design is done by someone else and the microcontroller that was chosen is Atmel's xMega128A1. So after writing some firmware the least amount of current that I managed to get is 619uA at 1.8V (In sleep mode). I have no previous experience with battery powered devices but this sounds like a lot to me. Also the datasheet says that the power consumption in those conditions should be 0.52uA... I know some manufacturers like to over exaggerate but the difference here is ~1240x. I have done everything that Atmel suggests through application notes and examples. Am I missing something? 

[benSTmax]

I don't have experience with the part you're using but the following recipes are good practices when designing low-power devices.
Check for other leakages on your board (e.g. resistor dividers), put all the MCU pins that have pull-ups, pull-downs as inputs, try to stop the oscillator.
Another trick is to keep the MCU in reset and measure the current. While in reset, the I/O pins are normally inputs and the oscillators should not run. If the current is around what you've measured, then you need to check outside the MCU for leakages.
If the current drops around the expected figure, then you have to do more in the firmware.
Good luck!

[ralphd]

With the tiny and mega AVRs you nees to disable brown-out detection during sleep to minimize power.

[Aleksandar B.]

After some more digging I found out that the JTAG draws a lot of current, but at the moment, for some unknown reasons, I can't disable it, neither trough firmware nor fuse bits.