The MAX1987 is dual-phase, Quick-PWM, step-down controllers for IMVP-IV CPU core supplies. Dual-phase operation reduces input ripple current requirements and output voltage ripple, while easing component selection and layout difficulties. The QuickPWM control scheme provides instantaneous response to fast load-current steps. The MAX1987/MAX1988 include active voltage positioning with adjustable gain and offset, reducing power dissipation and bulk output capacitance requirements. The MAX1987/MAX1988 are 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 these devices to directly step down highvoltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the 5V system supply instead of the battery) at higher switching frequency provides the minimum possible physical size. The MAX1987/MAX1988 meet the IMVP-IV specifications and can directly interface with the CPU powergood signals from the VCCP and VCCMCH rails within the system. The switching regulator features power-up sequencing, automatically ramping up to the Intelspecified boot voltage. The MAX1987/MAX1988 also feature independent four-level logic inputs for setting the boot voltage (B0 to B2) and the suspend voltage. The MAX1987/MAX1988 include output undervoltage protection, thermal protection, and system power-OK (SYSPOK) input. When any of these protection features detect a fault, the controller shuts down. Additionally, the MAX1987 includes overvoltage protection. The MAX1987/MAX1988 are available in a low-profile 48-pin 7mm ✕ 7mm Thin QFN package.
Dual-Phase, Quick-PWM Controllers
±0.75% VOUT Accuracy Over Line, Load, and Temperature
Active Voltage Positioning with Adjustable Gain and Offset
6-Bit On-Board DAC (16mV Increments)
0.492V to 1.708V Output Adjust Range
Selectable 200kHz/300kHz/550kHz Switching Frequency