SNVSBY7 March 2021 TPS92390
The maximum output LED current is set by an external resistor value. For the application only using external resistor RISET to set the maximum LED current for each string, the Equation 14 is used to calculate the current setting of all strings:
The LEDx_CURRENT[11:0] registers can also be used to adjust strings current down from this maximum. The default value for LEDx_CURRENT[11:0] registers is the maximum 0xFFF(4095). Equation 15 is used to calculate the current setting of an individual string:
For high accuracy of LED current, the ILED current is recommended to set in range from 30 mA to 200 mA. So the RISET value is in the range from 15.6 kΩ to 104 kΩ.