BQ2002T: Suggest Charger circuit For BQ2002T

Anand Sands

Prodigy 60 points

Part Number: BQ2002T
Other Parts Discussed in Thread: LM317

Hi All

Hope all are fine

BQ2002T how can we set chargine current or it has inbuilt fast charging means what is the charging rate ?

Either the charging current is adjustible or fixed

My specifications

Input : 5V 500mA USB

Battery: 2 cells NImh 1.2V /800 mAh

Charging current expected : 0.5C

Termination Style: Change in temperature /Cahnge in voltage

Can you guys give me a better circuit or recommend an IC which meets above specs in TI

over 4 years ago

0 Nick Brylski over 4 years ago

TI__Mastermind 19195 points

Hi Anand,

An example circuit for BQ2002T can be found here https://www.ti.com/lit/ug/sluu007b/sluu007b.pdf?ts=1594405120778

The charge current is set by the LM317 through R7. Battery voltage is set through resistor divider on the BAT Pin. This can be made to work for 2-cell operation, see section "Battery Voltage and Temperature Measurements" of d/s

Best,

0 Anand Sands over 4 years ago in reply to Nick Brylski

Prodigy 60 points

Thanks for the reply

My doubt in the above circuit diagram

What is above output voltage and output current for LM317

And which resistor we need to adjust for the required output voltage .

0 Anand Sands over 4 years ago in reply to Anand Sands

Prodigy 60 points

And How the CC pin controls the charging current

0 Nick Brylski over 4 years ago in reply to Anand Sands

TI__Mastermind 19195 points

Anand,

R7 sets output current of LM317, Battery voltage is set by R9/R14.

The LM317 section of this circuit does not need to be modified to work for 2 cell. Only need to change R9 to 101k.

Best,

Power management

Power management forum

BQ2002T: Suggest Charger circuit For BQ2002T