BQ40Z50-R2: Voltage in DSG not same in VCHG

dimas trilaksono

Part Number: BQ40Z50-R2

i Have problem in bq40z50r2 in measure Voltage in R8(DSG) from schematic not same in R11 or R3 (CHG).
what should I do to solve this problem?

over 6 years ago

0 Batt over 6 years ago

TI__Mastermind 42535 points

Both chg and dsg are overdrive pins that are driven by individual charge pumps. Therefore you can't have the same voltage across both of them.

0 dimas trilaksono over 6 years ago in reply to Batt

Prodigy 30 points

Thank u Batt for respon my question.
But if I in FET (on) measure at R8 (DC) it is measured 22V while at R11 (CHG) it is measured 11V and FET(off) R8 5V , R11 11V.
so what's wrong? i use batteray 11V

thank you,

dimas

0 Batt over 6 years ago in reply to dimas trilaksono

TI__Mastermind 42535 points

If you're using the bq40z50-r2 schematic from teh DS, R8 is the resistor on the PRES pin. That's maintained at a high voltage unless you want to press the shutdown switch to shut the gauge down. As I mentioned R11 is the gate drive to the chg fet. It will drive high when the fets are toggled. You need to send either the FET_EN or CHG_FET_TOGGLE command to turn it on.

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BQ40Z50-R2: Voltage in DSG not same in VCHG