Maxim MAX739 is an inverting switch-mode regulator utilizing a current-mode pulse-width modulation (PWM) controller to convert an unregulated input into a negative output voltage. The PWM controller provides precise output regulation, low subharmonic noise, cycle-by-cycle current limiting, overcurrent limiting, and programmable soft-start protection. It has a typical full-load efficiency of 83% and a no-load supply current of typically 1.7mA.

The device operates in either continuous or discontinuous mode, depending on the input voltage, output voltage, load current, and inductor value. It can also operate in either bootstrapped or non-bootstrapped mode to increase available output power.