Posted on December 11, 2017 at 20:21 
I have removed all the solder bridges & links to minimise stray consumption.
When I measure the combined current through JP3 and JP1 (ie, MCU & RF), it is ~0.87mA between Tx pulses.
(SB19,14,17 are removed; JP2 is not fitted - so no current to USB_LRA)
But, when I power the board from the battery, and measure the battery current, I see
1.95mA
(SB18 is removed)
The ST LD39050 regulator (U7) is supposed to be ''low quiescent current'': the datasheet says it should only, typically, be taking 100uA at 500mA load - so we should be nowhere near that!
So where is this extra milliamp going??
EDIT
To clarify: the ~0.87mA to MCU & RF is measured while powered from the battery.
#current-consumption #b-l072z-lrwan1 #low-power #current Note: this post was migrated and contained many threaded conversations, some content may be missing.
Posted on March 07, 2018 at 13:39 
You mean this:
EDIT
So what we actually have is this:
Which would seem like a strong suspect - well spotted!
I'll have to try it ...
Posted on March 07, 2018 at 16:15 
Jacques Grandjean wrote:
I can't see your second image.
Is this better:
But I can confirm you that if you remove D2, consumption from battery is in my case 20uA when I am in Stop mode (no other source of power connected) (18uA + current consumption MCU + Radio Stop mode)
Excellent.
- remove R26 as you mentionned
The undocumented feed from +3V3 to AIN_1 on the STLink
:(
you also need to remove SB37
Yes - that's the RESET from the STLink.
It seems that theB-L072Z-LRWAN1 is an example in how
not
to do a low-power design.:(
