TPS62730: Current consumption when ON/BYP low

Hi Jay,

Can you share your schematics? Did you check if VOUT=VIN when the ON/BYP is pulled low? 

Would be good to disconnect everything on the output to make sure there is nor load current on the output rail

Best regards,

Varun

Hello Varin,

Thanks for your quick support. Yes, I have checked when ON/BYP is low VIN=VOUT. Please see the image for the schematics.

Hi Jay,

Thanks for sharing the schematic.

• Could you please check input current after disconnecting R14?
• There is path from battery through R128 to ON/BYP (low). Are you checking the current from the battery or into the IC VIN pin?

Best regards,

Varun

Hello Varun,

After disconnecting the R14 it was varying between 1uA to 20uA. R128 is not mounted right now, we are checking the current in the DMM.

Regards,
Jay Kacha

Hi Jay,

Is there anything else passives/ICs running of the battery voltage? I think it makes sense to check the battery voltage with a scope since you mentioned the current is varying from 1uA to 20uA. Might be also worth testing with L2 shorted, in case there is some resonance caused by L2 and C48.

Best regards,

Varun

Hi Varun,

No nothing is running along with the battery. Battery voltage Is going to directly on the regulator. I will check with L2 shorted.

Regards,
Jay Kacha

Hi Jay,

Do you have any updates?

Best regards,

Varun

Hello Varun,

We have checked with the L2 shorted, current consumption settled down but it is 20uA.

Regards,
Jay Kacha

Hi Jay,

Thanks for checking. This was with R14 disconnected and L2 shorted right?

Have you verified the higher input current on a second unit or board? 

If possible can you send me a picture of the measurement setup and board layout to v-john@ti.com

Best regards,

Varun

Hi Varun,

It is with R14 mounted and L2 shorted, without R14 it is 1uA. I will share the photo with you of the measurement setup.

Regards,
Jay Kacha

Hi Jay,

Since the current is lower when the output rail is disconnected, it seems that there is something on the output rail that was consuming around 19uA of current. 

Best regards,

Varun

Hello Varun,

Yes, it seems MCU and the CC1101 is on the output taking the power on the output side.

Regards,
Jay Kacha

Hi Jay,

Could you check if your MCU and the CC1101 are in the correct operating state / low power mode? If you need help with the CC1101 you can create a new thread so that the right team is assigned to support you.

Best regards,

Varun

Hello Varun,

Yes both are in power-saving mode, I will put a separate thread for the CC1101. Thanks for the help.