CC2640: working with BQ24297/6 battery charger

Yosy Shmuly85

Prodigy 155 points

Part Number: CC2640
Other Parts Discussed in Thread: BQ24297, TPS62740

Want to operate the CC2640 using bq2497/6 battery charger

the Recommended Operating Conditions for VDDS, VDDS2, and VDDS3 when working with internal DC-DC is 1.8-3.8 Volts

the BQ24297 Vsys_Max is 4.35V.

how can I use the BQ24297 as a battery charger (Lithium-ion cell) and not exceeding the 3.8V CC2640 requirement?

over 8 years ago

0 Fredrik K over 8 years ago

TI__Guru** 106705 points

Hi Yosy,

I cannot find the battery charger IC you refer to. If the output voltage from the charger is above 3.8 V I recommend using a DCDC regulator, such as the TPS62740, and configuring the CC2640 for "external regulator mode". See this reference design for details: www.ti.com/.../cc2650em-4xs-ext-reg-rd

Regards,
Fredrik

0 Yosy Shmuly85 over 8 years ago in reply to Fredrik K

Prodigy 155 points

The battery charger is: BQ24297
www.ti.com/.../description

0 JXS over 8 years ago in reply to Yosy Shmuly85

TI__Guru** 105180 points

Hi Yosy,

Since the Vsys range is 3.5V-4.35V on this charger you will need to use a DCDC regulator, such as the one that Fredrik recommends.

Best wishes

0 Yosy Shmuly85 over 8 years ago in reply to JXS

Prodigy 155 points

I am looking for a solution without and additional Buck

Cant I change the charge level to 3.8V, using the following register and it will be ok?

0 Fredrik K over 8 years ago in reply to Yosy Shmuly85

TI__Guru** 106705 points

Hi Yosu,

That looks possible, but you should rather ask on the appropriate forum for BQ devices. I am not sure if it will be a problem with your LiIon cell if never fully charge it. I know there are chargers with built-in regulators, but again this is something the guys on the BQ forum can give better advice on.

Cheers,
Fredrik

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CC2640: working with BQ24297/6 battery charger