The MAX1718 step-down controller is intended for core CPU DC-DC converters in notebook computers. It features a dynamically adjustable output, ultra-fast transient response, high DC accuracy, and high efficiency needed for leading-edge CPU core power supplies. Maxim's proprietary Quick-PWM™ quick-response, constant-on-time PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns "instant-on" response to load transients while maintaining a relatively constant switching frequency.The output voltage can be dynamically adjusted through the 5-bit digital-to-analog converter (DAC) over a 0.6V to 1.75V range. The MAX1718 has an internal multiplexer that accepts three unique 5-bit VID DAC codes corresponding to Performance, Battery, and Suspend modes. Precision slew-rate control provides "just-in-time" arrival at the new DAC setting, minimizing surge currents to and from the battery.The internal DAC of the MAX1718B is synchronized to the slew-rate clock for improved operation under aggressive power management of newer chipsets and operating systems that can make incomplete mode transitions.A pair of complementary offset control inputs allows easy compensation for IR drops in PC board traces or creation of a voltage-positioned power supply. Voltage-positioning modifies the load-transient response to reduce output capacitor requirements and total system power dissipation.Single-stage buck conversion allows these devices to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the 5V system supply instead of the battery) at a higher switching frequency allows the minimum possible physical size.The MAX1718 is available in a 28-pin QSOP package.Applications2-Cell to 4-Cell Li+ Battery to CPU Core Supply Converters5V to CPU Core Supply ConvertersIMVP-II Notebook Computers