The AX3515A is a dual high-efficiency Pulse-Width-Modulated (PWM) step-down
DC-DC converter. It is capable of delivering 1A output current over a wide input voltage
range from 2.5V to 5.5V, the AX3515A is ideally suited for portable electronic devices that
are powered from 1-cell Li-ion battery or from other power sources within the range such as
cellular phones, PDAs and other handheld devices.
Two operational modes are available: PWM/Low-Dropout auto-switch and shutdown
modes. Internal synchronous rectifier with low RDS(ON) dramatically reduces conduction
loss at PWM mode. No external Schottky diode is required in practical application.
The AX3515A enters Low-Dropout mode when normal PWM cannot provide regulated
output voltage by continuously turning on the upper PMOS. The AX3515A enter shutdown
mode and consumes less than 0.1μA when EN pin is pulled low.
The switching ripple is easily smoothed-out by small package filtering elements due to
a fixed operation frequency of 1.4MHz. This along with small TDFN-10L (3x3) package
provides small PCB area application. Other features include soft start, lower internal
reference voltage with 2% accuracy, over temperature protection, and over current
protection.