The TPS61089x is a synchronous boost converter, integrating a 19-mΩ main power switch and a 27-mΩ rectifier switch with adjustable switch current up to 10 A. It is capable to output continuous power more than 18 W from input of a single cell Lithium-ion battery or two-cell Lithium-ion batteries in series. The TPS61089x operates at a quasi-constant frequency pulse-width modulation (PWM) at moderate to heavy load currents. At light load current, the TPS61089 operates in PFM mode and the TPS610891 operates in forced PWM (FPWM) mode. The PFM mode brings high efficiency over the entire load range, and the FPWM mode can avoid the acoustic noise and switching frequency interference at light load. The converter uses the constant off-time peak current mode control scheme, which provides excellent line and load transient response with minimal output capacitance. The external loop compensation brings flexibility to use different inductors and output capacitors. The TPS61089x supports adjustable switching frequency ranging from 200 kHz to 2.2 MHz. The device implements cycle-by-cycle current limit to protect the device from overload conditions during boost switching. The current limit is set by an external resistor.