The NCP1034 is a high voltage PWM controller designed for high performance synchronous Buck DC/DC applications with input voltages up to 100 V. The NCP1034 drives a pair of external N-MOSFETs. The switching frequency is programmable from 25 kHz up to 500 kHz allowing the flexibility to tune for efficiency and size. A synchronization feature allows the switching frequency to be set by an external source or output a synchronization signal to multiple NCP1034 controllers. The output voltage can be precisely regulated using the internally trimmed 1.25 V reference voltage for low voltage applications. Protection features include user programmable undervoltage lockout and hiccup current limit.