The step-down converter optimizes power efficiency throughout the load range. Pulling the MODE/SYNC pin high enables "PWM Only" mode, maintaining constant frequency and low output ripple across the operating range. Alternatively, the converter may be synchronized to an external clock input to the MODE/SYNC pin. The step-down converter delivers up to 800mA of output current, while consuming 30A of typical no load quiescent current. The switching frequency is 2MHz, minimizing the size of external components. The two LDOs (LDOA/LDOB) have independent inputs and are capable of delivering up to 150mA each. Ultra low input voltage on the VLDOA and VLDOB pins (down to 1.62V) allows for efficient post-buck regulation. A Power-OK (POK) function provides an open drain output signal when LDOA is within regulation. Both LDOs feature low quiescent current and a low dropout voltage. The output voltages for both LDOs are adjustable to as low as 0.6V. The linear regulators have independent Enable pins.