The ILC6383 series of step-up DC-DC converters operate from 1-cell to 3-cell input. They are direct replacement for ILC6382, in applications where SYNC pin is not used. The PFM or PWM operating mode is user selectable through SEL pin connected to ground or left open, respectively. The choice should be dependent upon the current to be delivered to the load: PFM is recommended for input voltage higher than 1.5V and loads below 100mA, while PWM is recommended for more than 50mA load current and in noise sensitive applications. In shutdown mode, the device allows true load disconnect from battery input. Designed for wireless communications applications, the oscillator frequency is set at 300kHz with no harmonics at sub 20kHz audio band or at 455kHz IF band.