ADP2503/ADP2504,datasheet,pdf(

The ADP2503/ADP2504 are high efficiency, low quiescent current step-up/step-down dc-to-dc converters that can operate at input
voltages greater than, less than, or equal to the regulated output voltage. The power switches and synchronous rectifiers are
internal to minimize external part count. At high load currents, the ADP2503/ADP2504 use a current-mode, fixed frequency
pulse-width modulation (PWM) control scheme for optimal
stability and transient response. To ensure the longest battery life in portable applications, the ADP2503/ADP2504 have an optional power save mode that reduces the switching frequency under
light load conditions. For wireless and other low noise applica-
tions where variable frequency power save mode may cause
interference, the logic control input sync forces fixed frequency
PWM operation under all load conditions.