The TPS6211x devices are a family of low-noise synchronous step-down dc-dc converters that are ideally suited for systems powered from a 2-cell Li-ion battery or from a 12-V or 15-V rail.The TPS6211x is a synchronous PWM converter with integrated N- and P-channel power MOSFET switches. Synchronous rectification is used to increase efficiency and to reduce external component count. To achieve highest efficiency over a wide load-current range, the converter enters a power-saving, pulse-frequency modulation (PFM) mode at light load currents. Operating frequency is typically 1 MHz, allowing the use of small inductor and capacitor values. The device can be synchronized to an external clock signal in the range of 0.8 MHz to 1.