BQ34110: Current calibration sign question

user4725373

Part Number: BQ34110

Hi,

I'm trying to understand the current calibration procedure. From the TRM, I should apply a known current at Rsense. There is a note there that says "The sign of current should be positive. Raw current samples are positive in discharge mode. This ensures that ccGain is positive."

This confuses me, as my battery connections are the same as the Simplified Schematic of the datasheet (+VBAT to BAT, -BAT to Rsense+ to SRP, GND to Rense- to SRN, see image below), but I read a negative current from the fuel gauge when the battery is discharging, and a positive current when it's charging.

Can you help me understand why it would be different in calibration? Are my connections wrong, and will that destroy the CEDV algorithm?

Thank you,

Fred

over 6 years ago

0 Batt over 6 years ago

TI__Mastermind 42535 points

A chg current should be +ve and dsg current should be -ve. So, please enter a -ve current in the calibration box when you're calibrating current.

0 user4725373 over 6 years ago in reply to Batt

Expert 1645 points

Ok, so I'm okay with the sign of the current. Is it a typo in the datasheet? Will this be corrected?

And you tell me to use a negative current as reference, but the datasheet says that the current should be positive to ensure a positive ccGain. What should I use?

Thank you,

Fred

0 Batt over 6 years ago in reply to user4725373

TI__Mastermind 42535 points

Negative current is always for dsg. You should get it right.

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BQ34110: Current calibration sign question