The NB681 is a fully integrated, high-frequency, synchronous, rectified, step-down, switch-mode converter with 2-bit VID, especially designed for IMVP8 applications—VCCIO, PRIMCORE, V1.0A, EDRAM, and EOPIO. It offers a very compact solution to achieve a 6 A continuous output current and a 7.5 A peak output current over a wide input supply range. The NB681 operates at high efficiency over a wide output current load range based on MPS proprietary switching loss reduction technology and internal low Ron power MOSFETs. Adaptive constant-on-time (COT) control mode provides fast transient response and eases loop stabilization. The DC auto-tune loop provides good load and line regulation. To avoid audible noise, NB681 provides low-power mode for power loss saving during the low-power state and ultrasonic mode. Full protection features include OC limit, OVP, UVP, and thermal shutdown. The converter requires a minimal number of external components, and it is available in a QFN 2mm x 3 mm package.