The MAX18066/MAX18166 current-mode, synchronous, DC-DC buck converters deliver an output current up to 4A with high efficiency. The devices operate from an input voltage of 4.5V to 16V and provides an adjustable output voltage from 0.606V to 90% of the input voltage. The devices are ideal for distributed power systems, notebook computers, nonportable consumer applications, and preregulation applications.The devices feature a PWM mode operation with an internally fixed switching frequency of 500kHz (MAX18066) and 350kHz (MAX18166) capable of 90% maximum duty cycle. The devices automatically enter skip mode at light loads. The current-mode control architecture simplifies compensation design and ensures a cycle-by-cycle current limit and fast response to line and load transients. A high-gain transconductance error amplifier allows flexibility in setting the external compensation, simplifying the design and allowing for an allceramic design.The synchronous buck regulators feature internal MOSFETs that provide better efficiency than asynchronous solutions, while simplifying the design relative to discrete controller solutions. In addition to simplifying the design, the integrated MOSFETs minimize EMI, reduce board space, and provide higher reliability by minimizing the number of external components.Additional features include an externally adjustable soft-start, independent enable input and power-good output for power sequencing, and thermal shutdown protection. The devices offer overcurrent protection (highside sourcing) with hiccup mode during an output shortcircuit condition. The devices ensure safe startup when powering into a prebiased output.The MAX18066/MAX18166 are available in a 2mm x 2mm, 16-bump (4 x 4 array), 0.5mm pitch wafer-level package (WLP) and are fully specified from -40°C to +85°C.ApplicationsDistributed Power SystemsHome Entertainment (TV and Set-Top Boxes)Network and DatacomPreregulators for Linear RegulatorsServers, Workstations, and Storage