Battery operated equipment, in an effort to maximize battery life, operates in burst modes where full or close to full current load is required for a short period of time before reverting to a standby mode where only a low current load is needed. This is typical of microcontroller and FPGA behavior and can also be found in wall powered equipment when targeting to be Energy Star compliant. At low output currents, light load conditions, a traditional constant frequency PWM-only converter would, therefore, suffer from a degraded efficiency performance. The ISL8202M and ISL8205M offer a selectable light load efficiency mode which greatly enhances efficiencies under low current conditions, achieving better than 85% efficiencies. Selection of the operational mode, PWM-only, or PWM/PFM mode for the ISL8202M and ISL8205M is simply achieved by connecting the SYNC pin to either the power rail or to ground. In PWM-only mode, operations are maintained at a constant frequency which mitigates any EMI concerns. In this mode and when operating with output currents below about 700 mA, switching losses significantly affect the overall conversion efficiencies. Selecting the PWM/PFM mode, however, forces the ISL8202M and ISL8205M to operate in a pulse skipping mode or burst mode when output currents fall below about 700 mA. While each pulse is still synchronized to the PWM clock, this mode effectively reduces the resulting operating frequency and greatly improves the light load efficiencies. Monitoring the bottom MOSFET for zero current crossing, the ISL8202M and ISL8205M enter into PFM mode once 16 consecutive cycles are detected. In this mode, the top MOSFET is driven to maintain the output between its nominal value and nominal +1.2% while the bottom MOSFET is maintained off. PWM operations resume as soon as the output voltage falls 2.5% below its nominal value. Further enhancing battery powered operations, the ISL8202M and ISL8205M also implement a 100% duty cycle LDO mode. When the input voltage drops too close to the selected output voltage to maintain regulation, which is typical of battery voltage decaying over time or in between charges, the ISL8202M and ISL8205M will stop switching operations and maintain the top MOSFET fully on for as long as possible, effectively operating as an LDO.