BQ2057W: D1 Position

Yoshinobu Kagawa

Expert 2030 points

Part Number: BQ2057W

Question about D1 position of BQ2057W.
The figure on the left is the standard circuit of the data sheet. Is it okay to set D1 at the position shown on the right?

The figure on the left shows the actual circuit used in the 2-series battery.
The figure on the right shows that the battery voltage wraps around with an M8 body diode and we want to reduce the standby current in the charging IC circuit.

Regards,
Kagawa

over 3 years ago

0 Nick Brylski over 3 years ago

TI__Mastermind 19195 points

Hi Kagawa,

We recommend D1 in the left position to prevent reverse current from from battery to input, by placing it after the FET it may not be as effect at preventing reverse current flow.

Best regards,

Nick

0 Yoshinobu Kagawa over 3 years ago in reply to Nick Brylski

Expert 2030 points

Hi Nick-san,

According to your answer, the standard left side is the recognition that the reverse current from the battery to the input and the wraparound are larger, but is it wrong?
Also, is it okay to recognize that there is no big problem if the reverse current can be prevented by the circuit shown on the right?

Regards,
Kagawa

0 Nick Brylski over 3 years ago in reply to Yoshinobu Kagawa

TI__Mastermind 19195 points

Hello Kagawa,

Please ignore my first post, the right configuration is fine and we have seen it before: e2e.ti.com/.../battery-drains-when-bq2057-charge-completed

Best regards,

Nick

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BQ2057W: D1 Position