BQ25892: Min / Max value of SYS_MIN

Hirokazu Takahashi

Expert 8420 points

Part Number: BQ25892

Dear Support team,

By setting SYS_min(REG03) on BQ25892, I think it is possible to stop the internal REGN and reduce power consumption.

For example, if you set SYS_min=3.3V, can you tell us the variation range of the voltage where the REGN actually stops?

We are currently using SYS_min = 3.3V.

Even at around 3.31-3.36V, the voltage and temperature may not be available.

I want to know what voltage setting with SYS_MIN to use to ensure that the temperature and voltage are obtained with VBAT=3.3V.

Best Regards,

Hirokazu Takahashi

over 2 years ago

0 Wyatt Keller over 2 years ago

TI__Guru** 102375 points

Hello Takahashi-san,

Can you specify which part of the datasheet you're referencing for the VSYS_MIN affecting REGN? The REGN will be supplied when the charger needs to switch, or if an ADC measurement is needed.

Section: 9.2.3.1 Power Up REGN Regulation (LDO) Discusses the criteria for the LDO.

Sincerely,

Wyatt Keller

0 user6101562 over 2 years ago

Prodigy 60 points

Hi Keller san,

> Can you specify which part of the datasheet you're referencing for the VSYS_MIN affecting REGN?

Regarding 9.2.8 Battery Monitor

When battery monitor is active, the REGN power is enabled and can increase device quiescent current. In
battery only mode, the battery monitor is only active when V(BAT) > SYS_MIN setting in REG03.

0 Wyatt Keller over 2 years ago in reply to user6101562

TI__Guru** 102375 points

Hello,

The REGN will pulse each time an ADC measurement is taken. If you do not have the monitoring enabled the REGN will not be active. If you have continuous conversion on every second, you should see REGN pulsing with each ADC measurement.

Sincerely,

Wyatt Keller

0 user6101562 over 2 years ago in reply to Wyatt Keller

Prodigy 60 points

Hi Keller san,

I understood about REGN.

We are currently using SYS_min = 3.3V.

Even at around 3.31-3.36V, Battery Monitor may not be available.

I want to know what voltage setting with SYS_MIN to use to ensure that the temperature and voltage are obtained with VBAT=3.3V.

0 Wyatt Keller over 2 years ago in reply to user6101562

TI__Guru** 102375 points

Hello,

Are you measuring directly at the SYS node of the charger? Sometimes with IR losses voltages can be slightly shifted depending on the node measured.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ25892: Min / Max value of SYS_MIN