MAX8743 Datasheet | Maxim Integrated

Description The MAX8743 is a dual pulse-width modulation (PWM) controller configured for step-down (buck) topologies that provides the high efficiency, excellent transient response, and high DC output accuracy necessary for stepping down high-voltage batteries to generate lowvoltage chipset and RAM power supplies in notebook puters. The CS_ inputs can be used with low-side sense resistors to provide accurate current limits or can be connected to LX_, using low-side MOSFETs as current-sense elements. High output impedance in shutdown eliminates negative output voltages, saving the cost of a Schottky diode at the output. The on-demand PWM controllers are free running, constant on-time with input feed-forward. This configuration provides ultra-fast transient response, wide input-output differential range, low supply current, and tight load-regulation characteristics. The MAX8743 is simple and easy to pensate. Single-stage buck conversion allows the MAX8743 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 MAX8743 is intended for generating chipset, DRAM, CPU I/O, or other low-voltage supplies down to 1V. The MAX8743 is available in 28-pin QSOP and 36-pin thin QFN packages. Applications Notebook puters CPU Core Supplies Chipset/RAM Supplies as Low as 1V 1.8V and 2.5V I/O Supplies Pin Configurations appear at end of data sheet. Quick-PWM and Dual Mode are trademarks of Maxim Integrated Products, Inc. Features - Ultra-High Efficiency - Accurate Current-Limit Option - Quick-PWM™ with 100ns Load-Step Response - 1% VOUT Accuracy over Line and Load - High Output Impedance in Shutdown - Dual Mode™ Fixed 1.8V/1.5V/Adj or 2.5V/Adj Outputs - Adjustable 1V to 5.5V Output Range - 2V to 28V Battery Input Range - 200k Hz/300k Hz/420k Hz/540k Hz Nominal Switching Frequency -...