The MAX1544 is a dual-phase, Quick-PWM™, step-down controller for AMD Hammer™ CPU core supplies. Dual-phase operation reduces input ripple current requirements and output voltage ripple while easing component selection and layout difficulties. The Quick-PWM control scheme provides instantaneous response to fast load-current steps. The MAX1544 includes active voltage positioning with adjustable gain and offset, reducing power dissipation and bulk output capacitance requirements.
The MAX1544 is intended for two different notebook CPU core applications: stepping down the battery directly or stepping down the 5V system supply to create the core voltage. The single-stage conversion method allows this device 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 provides the minimum possible physical size.
The MAX1544 complies with AMD's desktop and mobile CPU specifications. The switching regulator features soft-start and power-up sequencing, and soft-shutdown. The MAX1544 also features independent four-level logic inputs for setting the suspend voltage (S0-S1).
The MAX1544 includes output undervoltage protection, thermal protection, and voltage regulator power-OK (VROK) output. When any of these protection features detect a fault, the controller shuts down. Additionally, the MAX1544 includes selectable overvoltage protection.
The MAX1544 is available in a low-profile, 40-pin 6mm x 6mm thin QFN package. For other CPU platforms, refer to the pin-to-pin compatible MAX1519/MAX1545 and MAX1532/MAX1547 data sheets.
Key Features
Applications/Uses
Dual-Phase, Quick-PWM Controller
&#plusmn;0.75% VOUT Accuracy Over Line, Load, and Temperature (1.3V)
Active Voltage Positioning with Adjustable Gain and Offset
5-Bit On-Board DAC: 0.675V to 1.55V Output Adjust Range
Selectable 100kHz/200kHz/300kHz/550kHz Switching Frequency
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