The TPS51116 provides a complete power supply for DDR/SSTL-2, DDR2/SSTL-18, and DDR3 memory systems. It integrates a synchronous buck controller with a 3-A sink/source tracking linear regulator and buffered low noise reference. The TPS51116 offers the lowest total solution cost in systems where space is at a premium. The TPS51116 synchronous controller runs fixed 400kHz pseudo-constant frequency PWM with an adaptive on-time control that can be configured in D-CAP Mode for ease of use and fastest transient response or in current mode to support ceramic output capacitors. The 3-A sink/source LDO maintains fast transient response only requiring 20-μF (2 × 10 μF) of ceramic output capacitance. In addition, the LDO supply input is available externally to significantly reduce the total power losses.