PMIC Recommendation: Li-Ion 2.8 - 4.2V; Sys Volts: 3.3V

Husein Najmi

Other Parts Discussed in Thread: BQ40Z60, TPS63030, BQ24250, TPS65218, BQ25892, TPS63051, TPS630251

I am designing a consumer Li-ion powered system with the following constraints:

The system volts has to be 3.3V
Li-Ion battery charging range is 2.8 - 4.2V
Charging is to be done via a standard USB charger.
All aspects of battery charging - charging profile, safety timers, input current programming etc are expected.
[Desirable] the battery and system is isolated via switch.

I have been searching for "power management ICs" and "Li-ion battery chargers". So far my results have all yielded a battery charger IC only - on battery backup, system volts follow battery volts. I would want an internal buck-boost regulator to provide regulated 3.3V o/p.

e.g BQ40z60, TPS6502x, TPS6502xx etc

A boost regulator will not work since system volts need to be @ 3.3V (and not at 5V)

My current solution has a BQ24250 for the battery charging and then a TPS63030 as a buck-boost regulator. I would like a single IC to do the job.

Questions:

Are such ICs even available?
Please recommend some.

Thanks!

over 9 years ago

0 Michael Green over 9 years ago

TI__Genius 16870 points

Hi Husein,

How many rails do you have? We do have some PMICs with buck-boosts and many others with battery chargers. The TPS65218 has a buck-boost integrated into it. Otherwise, I recommend finding a PMIC with a battery charger and correct number of rails & features and add a buck-boost from the TPS63xxx family.

0 Husein Najmi over 9 years ago in reply to Michael Green

Prodigy 80 points

Just one rail @ 3.3V

0 Michael Green over 9 years ago in reply to Husein Najmi

TI__Genius 16870 points

Hi Husein,

That sounds more like a BQ part or 2 discretes as you are using today. PMICs at TI is more multi-rail devices. If you find that in addition to the 3.3V and battery charger, you also need a 1V and 1.8V or something that would be a PMIC.

I am going to more you post to the battery charger forum as I think the battery management team may have a device to match your needs.

0 Steven Bangdiwala over 9 years ago in reply to Michael Green

TI__Expert 8690 points

Husein,

I suggest looking into the bq25892. It has what you are looking for and its our latest device. To maintain steady 3.3V rail at system, you will need to add a buck/boost after the system pin, as battery voltage can go from 2.8V to 4.2V. There is currently no solution which involves one charger IC.

You can request the full datasheet and EVM user guide for bq25892 here: www.ti.com/.../swlicexportcontrol.tsp

Thanks,
Steven

0 Sabrina over 9 years ago in reply to Steven Bangdiwala

TI__Expert 8420 points

For a 3.3V regulated rail, I'd suggest to use TPS63051. If you require higher currents, please use TPS630251.
These devices can even handle the USB Voltage up to 5.5V.

0 Husein Najmi over 9 years ago in reply to Sabrina

Prodigy 80 points

Thanks for the replies everyone.

It seems:

PMIC are geared towards multiple rails - mostly step down, some also have step-up
What I am looking for - a single Li-ion charger with regulated o/p at 3.3V does not exist
So right now the solution is to use a buck boost regulator at the o/p of the BQ charger.

Power management

Power management forum

PMIC Recommendation: Li-Ion 2.8 - 4.2V; Sys Volts: 3.3V