NB685 Datasheet | Monolithic Power Systems

28V, 12A, Low Iq, High-Current, Synchronous Buck Converter with +/- 1A LDO and Buffered Reference DESCRIPTION The NB685 provides a plete power supply with the highest density for DDR3, DDR3L, LPDDR3, and DDR4 memory. It integrates a high-frequency, synchronous, rectified, stepdown, switch-mode converter (VDDQ) with a 1A sink/source LDO (VTT) and buffered low noise reference (VTTREF). The NB685 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 1A sink/source current capability and requires only 22μF ceramic capacitors. The VTTREF tracks VDDQ/2 with excellent 1% accuracy. Full protection Features include OC limit, OVP, UVP, thermal shutdown, and over-temperature warning (OTW). The converter requires a minimum number of external ponents and is available in a QFN 3mm x 3mm package. TYPICAL APPLICATION Features - Wide 4.5V to 28V Operating Input Range - patible for IMVP8 - 135μA Low Quiescent Current - 12A Continuous Output Current - 13A Peak Output Current - Selectable Ultrasonic Mode - Selectable 500k/700k Switching Frequency - Built-In +/- 1A VTTLDO - 1% Buffered VTTREF Output - Adaptive COT for Fast Transient - DC Auto-Tune Loop - Stable with POSCAP and Ceramic Output Capacitors - Over-Temperature Warning - Internal Soft Start - Output Discharge - OCL, OVP, UVP, and Thermal Shutdown - Latch-Off Re-Set via EN or Power Cycle - QFN 3mm x 3mm Package APPLICATIONS...