MAX1541

19-2861; Rev 3; 2/07 KIT ATION EVALU E L B AVAILA www.DataSheet4U.com Dual Step-Down Controllers with Saturation Protection, Dynamic Output, and Linear Regulator General Description The MAX1540A/MAX1541 dual pulse-width modulation (PWM) controllers provide the high efficiency, excellent transient response, and high DC-output accuracy necessary for stepping down high-voltage batteries to generate low-voltage chipset and RAM power supplies in notebook computers. The Maxim proprietary Quick-PWM™ controllers are free running, constant on-time with input feed forward. This configuration provides ultra-fast transient response, wide input-output (I/O) differential range, low supply current, and tight load-regulation characteristics. The controllers can accurately sense the inductor current across an external current-sense resistor in series with the output to ensure reliable overload and inductor saturation protection. Alternatively, the controllers can use the synchronous rectifier itself or lossless inductor current-sensing methods to provide overload protection with lower power dissipation. For a single step-down PWM controller with inductorsaturation protection, external-reference input voltage, and dynamically selectable output voltages, refer to the MAX1992/MAX1993 data sheet. Features ♦ Inductor-Saturation Protection ♦ Accurate Differential Current-Sense Inputs ♦ Dual Ultra-High-Efficiency Quick-PWMs with 100ns Load-Step Response ♦ MAX1540A 1.8V/1.2V Fixed or 0.7V to 5.5V...