If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Part Number: BQ25887

Hi,

My name is Babu,

In the datasheet that have been provided ,there is no details of reference voltage of 16 bit ADC. Can you tell me the reference working voltage of ADC?

In the register map section for REG17, it has mentioned "Sign bit: overall results reported in two's complement". Can you tell me what is the exact information that you want to convey here?

• Hi Babu,

For REG17, the register provides IBUS information in two's complement. This means that the most significant bit (REG17[7]) actually describes the sign (+/-) of the current reading. The register field descriptions provide a conversion from bit information to physical current information and therefore the bit[7] provides current direction information.

I believe the reference voltage for the ADC is an internal signal. I will update you with the ADC reference voltage when I learn more.

Best Regards,

Juan

• Thanks Juan Ospina for your valuable response. I have one more question can you tell me how we can convert if both IbUSADC1 and IBUSADC0 reads value how to convert that into physical value.

For example the IBUSADC1 reads 89 and IBUSADC0 reads 25, can you tell how to join and convert this value into physical current value.

• Hi Babu,

REG17 and REG18 combine to provide a 16 bit value for the ADC, with REG17 being the most significant byte. This means that if IBUSADC1 is 0x89 and IBUSADC0 is 0x25 then the full value is 0x8924

Converting it into a decimal value via two's complement, we attain a decimal value of "-30428" which will be the physical value in mA. So in this scenario the ADC is reading -30,428 mA for IBAT.

Best Regards,

Juan

• I think the final value will be 0X8925 am I right and thanks for clearing my simple basic doubt

• You're welcome

Best Regards,

Juan Ospina