LP8860-Q1: Selecting Current Sensing Resistor for LP8860-Q1 Power Input

Koji Hayashi92

Mastermind 7030 points

Part Number: LP8860-Q1

Hi All.

I cannot find "Selecting Current Sensing Resistor for LP8860-Q1 Power Input"

Although it is described in DataSheet's 7.12, it does not exist at the link destination.

Please teach me the URL.

Best Regards,

Koji Hayashi

over 6 years ago

0 Shirley He over 6 years ago

TI__Expert 5475 points

Hi,

Sorry the application note is not released online. The LP8860 device uses the voltage across the Risense resistor for input ocp detection. Assuming Risense is 20mohm, different input current ocp limit can be achieved by using different PL_SD_LEVEL[1:0], as the table below shows. So the Risense value depends on the required current limit and the selected PL_SD_LEVEL[1:0] code.

0 Koji Hayashi92 over 6 years ago in reply to Shirley He

Mastermind 7030 points

Hi Shirley-san

Thank you for quick response.

Is the threshold calculation correct with the formula below ?

20mohm * 6A=0.12V

20mohm * 8A=0.16V

If so, if the resistance is changed to 10mΩ, will the over current be 12A and 16A ?

0.12V / 10mohm =12A

0.16V / 10mohm =16A

Best Regards,

Koji Hayashi

0 Shirley He over 6 years ago in reply to Koji Hayashi92

TI__Expert 5475 points

Hi,

Yes, your understanding is right.

0 Koji Hayashi92 over 6 years ago in reply to Shirley He

Mastermind 7030 points

Hi Shirley-san

Thank you for quick response.

I understand.

Best Regards,

Koji Hayashi.

Power management

Power management forum

LP8860-Q1: Selecting Current Sensing Resistor for LP8860-Q1 Power Input