The TPS61023 is a synchronous boost converter designed to operate from an input voltage supply range between 0.5 V and 5.5 V with a typically 3.7-A valley switch current limit. The TPS61023 typically operates at a quasi-constant 1-MHz frequency PWM at moderate-to-heavy load currents when the input voltage is above 1.5 V. The switching frequency changes to 0.5 MHz gradually with the input voltage changing from 1.5 V to 1 V for better efficiency and high step-up ratio. When the input voltage is below 1 V, the switching frequency is fixed at a quasi-constant 0.5 MHz. At light load currents, the TPS61023 converter operates in power-save mode with PFM to achieve high efficiency over the entire load current range.