The APW7108 is a dual-channel, constant on-time, and synchronous PWM controller which drives dual Nchannel MOSFETs for each channel. The APW7108 steps down high voltage of a battery to generate low-voltage chipset or RAM supplies in notebook computers. The APW7108 provides excellent transient response and accurate DC voltage output in either PFM or PWM mode. In PFM mode, the APW7108 provides very high efficiency over light to heavy loads with loading-modulated switching frequencies. The Forced-PWM mode works nearly at constant frequency for low-noise requirements. The APW7108 is equipped with accurate current-limit, output under-voltag, and output over-voltage protections, perfect for NB applications. A Power-On-Reset function monitors the voltage on VCC to prevent wrong operation during power on. A soft-start ramps up the output voltage with programmable slew rate to reduce the start-up current. A soft-stop function actively discharges the output capacitors with controlled reverse inductor current. At the end of the soft-stop, the APW7108 forces LGATE high to prevent over-voltage in shutdown. The APW7108 has individual enable controls for each channel. Pulling both EN pin low shuts down the whole chip with low quiescent current close to zero. The APW7108 is available in SSOP-28 and QFN4x4-24 packages.