BQ40Z50-R2: Internal ADC reference voltage

Carlo Marsano

Part Number: BQ40Z50-R2

Hi Team,

How is the internal 1.225V ADC reference voltage derived?

Is it from the REG33, REG25 or from the BAT supply?

This isn’t clear from the block diagram or the datasheet.

Thanks, Carlo.

0 Batt over 7 years ago

It's probably an internal bandgap. I'll confirm tomorrow after talking to the hw engineers.

0 Batt over 7 years ago in reply to Batt

Both ADC and CC share a separate dedicated bandgap that's internal referred to in the DS as Vref1.

0 Carlo Marsano over 7 years ago in reply to Batt

Thanks & Apologies Guys,

The question related to the bq20z95 and not the bq40z50-R2.

Also, I wanted to know which rail supplies the bandgap reference.

Thanks, Carlo.

0 Batt over 7 years ago in reply to Carlo Marsano

Power comes from the cell input. That's VCC. The power to the bandgap is internal to the chip and is not brought out. from REG25.

0 Batt over 7 years ago in reply to Batt

Power management forum