AX3503 is a high efficiency monolithic synchronous buck regulator using a constant
    frequency, current mode architecture. The device is available in an adjustable version.
    Supply current with no load is 35uA and drops to <1uA in shutdown. The 2.5V to 6V input
    voltage range makes AX3503 ideally suited for single Li-Ion, two to four AA battery-powered
    applications. 100% duty cycle provides low dropout operation, extending battery life in
    portable systems. PWM pulse skipping mode operation provides very low output ripple
    voltage for noise sensitive applications. Switching frequency is internally set at 1.5MHz,
    allowing the use of small surface mount inductors and capacitors. The internal synchronous
    switch increases efficiency and decreases need of an external Schottky diode. Low output
    voltages are easily supported with the 0.6V feedback reference voltage. AX3503 is available
    in small SOT-23-5L and TDFN-6L (2*2) packages.


    Package Type (T)SOT23-5,TDFN6
    Input Voltage (Max) 6V
    Output Current 1A
    Output Voltage Adj(Vfb=0.6V)
    Frequency 1.5MHz
    Shutdown Current 0.1uA
    5 to 3.3V Efficiency(%) 92(0.5A)
    Availability NOW