MAXIM 1540, MAX1540A, 1540AEThe 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. A
