The power dissipation of the MAX16814 comes from two sources : 1. The current consumption of the IC itself (VIN x ICC) where ICC is the MAX16814 quiescent current consumption typically 2.5mA 2. The current required to drive the external MOSFET; (VIN – 5V) x (Qg x fsw) where VIN is the voltage at the IN pin of the IC, Qg is the total gate charge of the chosen MOSFET at 5V, and f sw is the switching frequency . The t otal power dissipation of the MAX16814 can be estimated using the following equation: Ptotal = VIN x ICC + (VIN – 5) x (Qg x fsw)