Using BQ40Z50-R2 fuel gauge IC,

refer to TI technical manual for circuit schematic diagram,

set IC into Sleep mode, charge MOS off, discharge MOS on,

no communication, use ammeter to test circuit self-consumption,

test 170uA, TI technical manual says Only 75uA, I am puzzled

Hi Nick,

How is 75uA tested?

Is it tested with the typical schematic diagram of BQ40Z50-R2?

We have tested a lot, basically around 175uA, so I am very confused about how 75uA is tested?

Hi Scofield,

Do you have the SMBUS pullups connected? This could be why your seeing higher power still.

BR,

Nick

Hi Nick,

I did not do this,

I know that the IC will increase its own power consumption under communication conditions

Is 75uA tested using the typical schematics in the BQ40Z50-R2 data sheet?

Or use other circuit diagrams for testing?

Hi Scofield,

It is tested using the application schematic (fig 21) found in the datasheet, yes. The 75uA is only a typical value, and varies depending on system implementation. Can you upload your schematic here for review?

Best regards,

Nick

Hi Nick,

Our schematic diagram uses two BQ40Z50-R2,

after entering Sleep mode,

the self-consumption is 340uA.

Hi Nick,

Why is the voltage of the CHG pin about 7.2V after the battery enters sleep mode?

Hi Nick,

Is it normal for the self-consumption of two BQ40Z50-R2 to reach 340uA?

How can I achieve a self-consumption of 75uA after a single IC enters Sleep mode?