¡El APW8861 integrates a synchronous buck PWM converter to generate VDDQ, a sourcing and sinking LDO linear regulator to generate VTT. It offers the lowest total solution cost in system where space is at a premium. ¡El APW8861 provides excellent transient response and accurate DC voltage output in either PFM or PWM Mode. In Pulse Frequency Mode (PFM), the APW8861 provides very high efficiency over light to heavy loads with loadingmodulated switching frequencies. On TQFN-32 Package, the Forced PWM Mode works nearly at constant frequency for low-noise requirements. ¡El APW8861 is equipped with accurate current-limit, output under-voltage, and output over-voltage protections. A Power-On- Reset function monitors the voltage on VCC prevents wrong operation during power on. ¡El LDO is designed to provide a regulated voltage with bi-directional output current for DDR-SDRAM termination. ¡El device integrates two power transistors to source and sink current up to 1.5A. It also incorporates currentlimit and thermal shutdown protection. ¡El output voltage of LDO tracks the voltage at VREF pin. An internal resistor divider is used to provide a half voltage of VREF for VTTREF and VTT Voltage. ¡El VTT output voltage is only requiring 20mF of ceramic output capacitance for stability and fast transient response. ¡El S3 and S5 pins provide the sleep state for VTT (S3 state) and suspend state (S4/S5 state) for device, when S5 and S3 are both pulled low the device provides the soft-off for VTT and VTTREF.