External MOSFET Reduces I²R Losses in Smart Power Selector™-Based Chargers

By: Hubert Bugajski

Abstract: Battery-to-system (BAT-to-SYS) connection impedance is critical and affects battery runtime by reducing headroom and dissipating power. An external pass transistor lowers the impedance by more than 50%. This application note shows the MAX8662 power-management IC with Smart Power Selector functionality drives an external MOSFET to reduce switch resistance and power dissipation. Performance data are shown.