BQ51050B: Wireless charging solutions

Conor

Part Number: BQ51050B
Other Parts Discussed in Thread: BQ25170, BQ25100, BQ51003, BQ25180, BQ25120, BQ25155, TIDA-00318

Tool/software:

Hi,

Q1.
As far as TI's lineup is concerned, the only charger IC that supports wireless charging is the bq5105x. When selecting an IC, it is not necessary to be "Qi-Compliant," and the most important thing is to make the system compact. Are there any charger ICs other than the bq5105x that you can suggest?

The target battery is a 1-cell coin battery.
https://www.powerstream.com/p/Lir1620.pdf

Other companies seem to offer solutions for mobile applications for coin batteries that can be charged via NFC. I would like to know if there are any similar products.

Q2.
We are also considering a system that charges the above 1-cell coin battery via USB rather than wirelessly. BQ25170 and others seem to be applicable, but the following specifications are required.
-Power pass-through
-Ship mode (a function that prevents the coin battery from being depleted as much as possible when shipped)

Are there any products that you can suggest?

Thanks,

Conor

3 months ago

+1 Bill Johns 3 months ago

TI__Guru 70006 points

Hi Conor

Conor said:
Are there any charger ICs other than the bq5105x that you can suggest?

The battery LIR1620 is 4.2V with charge current of 5mA to 10mA. BQ5105X will not support this low a charge current

We have a low power application circuit see TIDA-00318.

This is a two IC solution BQ51003 + BQ25100, the battery charger can be replaced with BQ25170 that will work better at low charge currents.

Conor said:
Are there any products that you can suggest?

Checking on this one, the BQ25120 or BQ25180 may work.

0 Bill Johns 3 months ago in reply to Bill Johns

TI__Guru 70006 points

Hi Conor

Also take a look at the BQ25155, it is power path with ship mode and low charge current accuracy.

0 Conor 3 months ago in reply to Bill Johns

Mastermind 9800 points

Hi Bill,

Bill Johns said:
This is a two IC solution BQ51003 + BQ25100, the battery charger can be replaced with BQ25170 that will work better at low charge currents.

This is good information! Since the BQ51003 complies with Qi, the frequency will be higher and the external coil is expected to be larger.
The application requires miniaturization. Do you have any advice?

Thanks,

Conor

0 Bill Johns 3 months ago in reply to Conor

TI__Guru 70006 points

Hi Conor

Coil size -- TIDA-00318 will use the TDK WR222230, this is a good small coil. It is 22mm in diameter and has been used on other designs. Have had bad luck with coils below 15mm, 15mm to 20mm is a gray area, try to stay above 20mm.

How small a coil are you looking for?

0 Conor 3 months ago in reply to Bill Johns

Mastermind 9800 points

Hi Bill,

Bill Johns said:
How small a coil are you looking for?

A thickness of at least 20mm is required.
The thickness also needs to be kept as small as possible, so this also needs to be taken into consideration.

Thanks,

Conor

+1 Bill Johns 3 months ago in reply to Conor

TI__Guru 70006 points

Hi Conor

The WR222230-26M8-G (WR222230) would meet the 20mm requirement.

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BQ51050B: Wireless charging solutions