The MAX17250 has a three-state ISET input pin used to select the inductor peak current limit (IPEAK), as shown in the Table.
ISET IPEAK (A)
VL 3.5
AGND 2.7
OPEN 1.85
ISET value is read when VL crosses its UVLO threshold during power-up, or when EN transitions low-to-high. (See VL UVLO in the Electrical Characteristics table).
The inductor peak current limit setting should be determined as follows:
1. Calculate the inductor ripple current (ΔI) using the equation below.
ΔI=VIN_MIN×tONL, where VIN_MIN is the minimum input voltage, tON is the 800ns on time.
2. Calculate the maximum input current (IINPEAK) using the equation below:
IINPEAK=VOUT×IOUTVINMIN×η+ΔI