LORA-E5-LE-HF goes high in current consumption with and without fw application running


I have recently acquired some Lora-E5-LE-HF (Low Energy) modules for replacing the Lora-E5-HF module that I have been using on a product I’m developing.
So, I simply removed the module I had on the board, soldered the new one (Low Energy) and programmed the same firmware application, changing only one line on the code where I define if it is HP or LP.
When I used the Low energy version, I commented out the RBI_CONF_RFO_HP.

When starting the device the current consumption was extremely high, around 50mA.
I have an image for it, but I’ll upload later, since I can use only one image in my post and I want to highlight another image here.

Immediately I though it was a solder bridge or something like that, but there was no such a thing on the board.

Then I changed the chip and it occurred again.

So I decided to test both chips Lora-E5-HF and Lora-E5-LE-HF without any firmware application running, I mean, as it comes “from the shelf”.

After some time, approximately 40 seconds the Lora-E5-LE-HF started to increase the current consumption until I decided to turn it off. See the pictures below comparing the Lora-E5-HF vs Lora-E5-LE-HF:

It is important to say that I used the same PCB and it is very unlikely that something is wrong with the soldering since it was checked before turning on and also because the PADs are quite big and easy to solder and check if there is any solder bridge. Also, if any soldering issue was there from the beginning, this issue would start right away and also would have happened to the Lora-E5-HF module.

Is there anyone else experiencing this?
Any tips? It has been quite complicated to debug it since everything works fine with Lora-E5-HF module and the opposite with Lora-E5-LE-HF module.

Best regards,

Hi there,
Sounds like it’s trying to Transmit? , and 50ma. is about right for full blast @125ish ? db :slight_smile:
I would check the GND’s be sure no loops exist. try some jumper wires on all the ground pins.
what kind of power supply?
GL :slight_smile: PJ :christmas_tree:

Hi PJ,

Thanks for your tips. I can do that, but it is unlikely that the GND is floating.
About the trying to transmit you said, this is also not the case since when starting up the fw does not send a message.
When transmitting it should be around 26mA for the low energy chip when the power output is 14dBm.

But, I agree that it seems like something is floating here, but then it would be internally in the chip.

I’m using an OTII power supply to check the current consumption.

Best regards,

Hi Vinicius,

Did you ever get to the bottom of this? - I am interested in using the low power version of this chip and wondered if you managed to get it to work correctly in the end?



I have both LoRa-E5-HF and LoRa-E5-LE-HF, but the current consumption is as shown in the link below. I have not had any problems.

Hi @mikeyd0407,

It seems it was a soldering issue on the other components on the PCB.

I started checking the other components I have on the board. I removed one by one until the problem is fixed. I found out that 2 components could be the reason of this behavior. So, I removed them and soldered them back and it seems like it worked.
I don’t believe it is an issue with the LORA-E5 chip, but when heating up the PCB to change the LORA chips, the other components on the board might have moved or got a bad solder connection.

I have now 5 boards that are working fine and the solution was, as I said, re-soldering the surrounding components.
I hope this was the case. I have ordered a new batch of boards (with the LE chip) and I’ll test it without changing anything on the PCB :slight_smile:

Best regards,

Hi @msfujino

I have the same scenario here. The boards that are working properly the consumption is exactly what you showed. So, I don’t believe it is an issue with the LORA-E5 chips.

Best regards,