I swapped some components and now my sleep power is 500uA instead of 160uA. Anyone wants to help finding out where it comes from?

Thread Starter


Joined Dec 17, 2015
I have a PCB (actually, many...) that was designed with an LT1129CST-3.3 LDO but it was quiet a pricy component so it was swapped with a TLV76733DRVR alternative. At the same time the LoRa modue was swapped with a Murata LoRaWan module (CMWS1ZZABZ-078). This LoRaWan module should not be consuming more power while in sleep. It is supposed to a couple uA only. Other than this, the PCB didn't change at all.

Yet, we now measure about 500uA total PCB power consumption while it was about 160uA with the previous PCB version.

Could it be the TLV767 that's consuming much more power compared to the LT1129?
Even while both report low quiencient current in their datasheets?

Our PCB was designed to allow both the TLV767 or the LT1129. We could try manually removing the TLV767 and manually soldering the LT1129 to fix the PCB. But before I try that I would like to hear what others think. Could the TLV767 be the cause?

If the TLV767 cannot cause this it must be the LoRaWan module but that's weird too, because this module is exactly the same used on Arduino MKR WAN 1310 boards and those boards sleep at 18uA...