Dual-Phase, Quick-PWM Controllers for Programmable CPU Core Power Supplies

The MAX1519/MAX1545 are dual-phase, Quick-PWM™, step-down controllers for desktop and mobile Pentium® 4 (P4) 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 MAX1519/MAX1545 include active voltage positioning with adjustable gain and offset, reducing power dissipation and bulk output capacitance requirements.

The MAX1519/MAX1545 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 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 MAX1519/MAX1545 comply with Intel's P4 specifications. The switching regulator features soft-start, power-up sequencing, and soft-shutdown. The MAX1519/MAX1545 also feature independent four-level logic inputs for setting the suspend voltage (S0-S1).

The MAX1519/MAX1545 include output undervoltage protection (UVP), thermal protection, and voltage regulator power-OK (VROK) output. When any of these protection features detect a fault, the controller shuts down. Additionally, the MAX1519/MAX1545 include overvoltage protection.

The MAX1519/MAX1545 are available in low-profile, 40-pin, 6mm x 6mm thin QFN packages. For other CPU platforms, refer to the pin-to-pin compatible MAX1544 and MAX1532/MAX1546/MAX1547 data sheets.

Applications

* Desktop and Mobile P4 Computers * Low-Voltage, Digitally Programmable Power Supplies * Multiphase CPU Core Supplies * Servers/Desktop Computers * Voltage-Positioned Step-Down Converters

* Dual-Phase, Quick-PWM Controllers

* ±0.75% VOUT Accuracy Over Line, Load, and Temperature (1.3V)

* Active Voltage Positioning with Adjustable Gain and Offset

* 5-Bit On-Board DAC

* Mobile: 0.60V to 1.75V Output Range

* Desktop: 1.10V to 1.85V Output Range

* Selectable 100kHz/200kHz/300kHz/550kHz Switching Frequency

* 4V to 28V Battery Input Voltage Range

* Adjustable Slew-Rate Control

* Drive Large Synchronous Rectifier MOSFETs

* Output Overvoltage Protection (MAX1545 Only)

* Undervoltage and Thermal-Fault Protection

* Power Sequencing and Timing

* Selectable Suspend Voltage (0.675V to 1.45V)

* Soft-Shutdown

* Selectable Single- or Dual-Phase Pulse Skipping