BQ24093: About the charging current setting problem

Chenkai Wang

Part Number: BQ24093

The previous design I set the current resistor R403 set to 6.04K, the theoretical charging current is 540/6.04 = 89mA, and the actual test out the same value.
But currently I want to get about 140mA charging current, I set R403 to 3.9K, theoretical charging current is 540/3.9 = 138mA, but the actual test out charging current is still 90mA.

I tested two pieces of mainboard results are like this, why the charging current will not change?
Can you help me to confirm the problem? Thanks

over 4 years ago

0 Anthony P Pham over 4 years ago

TI__Mastermind 23410 points

Hi Chenkai,

Can you measure the voltage at the ISET pin and TS pin? Also please verify that the ISET2 pin is low. Overall, I don't see any issues with the schematic at first glance. W

0 Chenkai Wang over 4 years ago in reply to Anthony P Pham

TI__Prodigy 190 points

Hi, Anthony

Thanks for your kindly reply.

I checked the voltage as below:

TS=0.4V ISET=1.5V ISET2=0V

Thanks

0 Anthony P Pham over 4 years ago in reply to Chenkai Wang

TI__Mastermind 23410 points

Hi Chenkai,

It seems that the device does believe it is charging at it's max charge current. Can you measure the ISET pin to GND resistance and see it if measures the expected 3.9k?

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BQ24093: About the charging current setting problem