The NB685A provides a complete power supply with the highest power density for DDR3, DDR3L, LPDDR3, and DDR4 memory. It integrates a high-frequency, synchronous, rectified, step-down, switch-mode converter (VDDQ) with a 1 A sink/source LDO (VTT) and buffered low noise reference (VTTREF). The NB685A 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. The VTT LDO provides 1 A sink/source current capability and requires only a 22 ? ceramic capacitor. The VTTREF tracks VDDQ/2 with excellent 1% accuracy. Full protection features include OC limit, OVP, UVP, over-temperature warning (OTW), and thermal shutdown. The converter requires a minimum number of external components and is available in a QFN 3mm x 3mm package.