BQ24002: BQ24002 input current

user5850523

Part Number: BQ24002
Other Parts Discussed in Thread: BQ24040, BQ24072, BQ21040, BQ24232, BQ24090, BQ24083

hi
I have a question
BQ24002 data sheet indicates that VCC current is 1mA
60mA when output current is precharged
But when I use the actual circuit, I find that the output current is related to the input current. When the output current is 60mA, the input current must also be maintained at 60mA. What is the reason for this?
Can you recommend some current charging chips

Thank you
best wishes

over 6 years ago

0 Raheem over 6 years ago

TI__Mastermind 21590 points

Hello,

What charge current do you need? I'll suggest looking at the BQ24232 or the BQ24072. The BQ21040 and BQ24040 are also popular devices that are similar to the BQ24002.

0 Bill Johns over 6 years ago

TI__Guru* 77366 points

Hello

The BQ24002 is an older generation of linear charger.

A newer device that may meet your requirements is the BQ24040 or BQ24090. If 4.1V battery charge voltage is required the BQ24083 may be an option.

0 user5850523 over 6 years ago in reply to Raheem

Prodigy 150 points

thank you, I want to know the limitation of the input current of BQ24002, it is 1mA of VCC pin right?

0 user5850523 over 6 years ago in reply to Bill Johns

Prodigy 150 points

thank you, I want to know the limitation of the input current of BQ24002, it is 1mA of VCC pin right?

0 Bill Johns over 6 years ago in reply to user5850523

TI__Guru* 77366 points

Yes, Input current to VCC pin is 1mA maximum.

0 user5850523 over 6 years ago in reply to Bill Johns

Prodigy 150 points

thank you

so when input cuurent is 1mA, the output current can reach to 60mA-1A, is it right?

best ragards

0 user5850523 over 6 years ago in reply to Bill Johns

Prodigy 150 points

so when input cuurent is 1mA, the output current can reach to 60mA-1A, is it right?

0 Bill Johns over 6 years ago in reply to user5850523

TI__Guru* 77366 points

Hello

The VCC pin input current is specified as 1mA max. This is the power used internal to IC and going into this pin.

Current going to battery is applied to the IN pin. In a precharge condition set by battery voltage this current is limited to 60mA, +/-20mA. This is current going to battery.

"so when input cuurent is 1mA, the output current can reach to 60mA-1A, is it right?" -- Bill J -- In this device VCC and IN are separate. Total current will be in the range of 60mA + 1mA.

"But when I use the actual circuit, I find that the output current is related to the input current. When the output current is 60mA, the input current must also be maintained at 60mA. What is the reason for this?." -- Bill J this sound correct as a linear charger the BQ24002 input and output current are the same.

0 user5850523 over 6 years ago in reply to Bill Johns

Prodigy 150 points

Thank you for your reply
I also want to ask,
1 According to the typical application circuit diagram, both the IN pin and the VCC pin are connected to VCC, so if the VCC input is 5V / 0.5A, a voltage of 5V flows into the VCC pin and a 0.5A current flows into the IN pin.

2 Regarding the charging process, if the battery voltage is less than lowV, pre-charge is started for 22.5min, and the charging current is 60mA + -20mA. If the voltage is greater than lowV and less than overv, constant current charging is started, and the charging current and input current are consistent with 0.5A, charging Constant voltage charging starts at 4.2V. Is this correct?

3 If I want some charging chip with low input current but high output current, is there such a charging chip?

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BQ24002: BQ24002 input current