BQ24192i minimum Sys Out in battery mode

Bhupendar Singh87136

Other Parts Discussed in Thread: BQ24192I

Hi,

We are planning to use BQ24192i in one of our design and using a Single cell battery in system. We are feeding the output of BQ24192i (VSYS) to input of Power Management chip which has input range 3.5V-5.5V.

In scenario when system is working only on battery( No input at VBUS) .If Battery voltage goes below 3.5V . ( For example 2.8V-3.4V) what will be the VSYS output .

1. Will It cut off the power if battery voltage goes below 3.5V

2. Will it follow the Battery voltage as there is no boost circuit shown in block diagram

3. Or still it can provide 3.5V till some level.

4. What is the minimum battery voltage for which BQ24192i can provide 3.5V-4.2V at output .

Thanks & Regards,

Bhupendar

over 11 years ago

0 Charles Mauney over 11 years ago

TI__Mastermind 31120 points

When VBUS is disconnected and running off the battery the BAT FET directly connects the battery to the system so system voltage is a few millivolts (IR drop) below the battery voltage.

A1) The BAT FET will not turn off until the battery drops to ~2.5V, which should not be a big issue since the cell would have no capacity below 2.8V.

A2) no boost ckt, just direct connect

A3) No, battery is directly connected to system

A4) No boost.

0 Bhupendar Singh87136 over 11 years ago in reply to Charles Mauney

Prodigy 200 points

Thanks a lot for a quick clarification!

Power management

Power management forum

BQ24192i minimum Sys Out in battery mode