The NX2138 controller IC is a compact Buck controller n IC with 16 lead MLPQ package designed for step down n DC to DC converter in portable applications. It can be n selected to operate in synchronous mode or non-syn- n chronous mode to improve the efficiency at light n load.Constant on time control provides fast response, good line regulation and nearly constant frequency un- n der wide voltage input range. The NX2138 controller is optimized to convert single supply up to 24V bus voltage to as low as 0.75V output voltage. Over current n protection and FB UVLO followed by latch feature. Other n features includes: internal boost schottky diode, 5V gate n drive capability, power good indicator, over current pro- n tection, over voltage protection and adaptive dead band n control.