The peak input current is set by selecting the correct external resistor value correlating to the required current limit. Since the TPS61088 is configured to work in PFM mode in light load condition, use Equation 6 to calculate the correct resistor value:

Equation 6.

where

• R_ILIM is the resistance connected between the ILIM pin and ground
• I_LIM is the switching peak current limit

For a typical current limit of 11.9 A, the resistor value is 100 kΩ. Considering the device variation and the tolerance over temperature, the minimum current limit at the worst case can be 1.3 A lower than the value calculated by Equation 6. The minimum current limit must be higher than the required peak switch current at the lowest input voltage and the highest output power to make sure the TPS61088 does not hit the current limit and can still regulate the output voltage in these conditions.