Simplified Block Diagram
Click any title below to view the detail page where available.
- 3-/4-Phase Interleaved Fixed-Frequency Controller
- ±0.75% VOUT Accuracy Over Line, Load, and Temperature
- 5-Bit On-Board Digital-to-Analog Converter (DAC)—0.80V to 1.55V
- Adjustable Suspend Voltage Input
- Active Voltage Positioning with Adjustable Gain and Offset
- Accurate Lossless Current Balance
- Accurate Droop and Current Limit
- Remote Output and Ground Sense
- Output Slew-Rate Control
- Power-Good Window Comparator
- Selectable 200kHz/300kHz/600kHz Switching Frequency
- Output Overvoltage and Undervoltage Protection
- Thermal Fault Protection
- 2V ±0.7% Reference Output
- Soft-Startup and Shutdown
- AMD Hammer Desknote Computers
- Multiphase CPU Core Supplies
- Notebook and Desktop Computers
- Voltage-Positioned Step-Down Converters
The MAX8707 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 these devices to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, 2-stage conversion (stepping down the +5V system supply instead of the battery) at higher switching frequency provides the minimum possible physical size.
The MAX8707 features dedicated differential currentsense inputs for each phase and includes a fifth pair of current-sense inputs to provide an accurate voltagepositioning slope and average current-limit protection using a single current-sense resistor. The MAX8707 also has two dedicated inputs that provide differential remote voltage sensing.
The MAX8707 provides an analog input for setting the suspend voltage and a slew-rate controller for transitions between VID codes or the suspend voltage. The controllers reduce the transition slew rate during startup and shutdown, providing soft-start with minimal input surge current and damped soft-shutdown without negative output undershoot. The MAX8707 includes output fault protectionundervoltage, nonlatched overvoltage, and thermal overloadand an independent voltageregulator power-OK (VROK) output.
The MAX8707 has a selectable switching frequency, allowing 200kHz, 300kHz, or 600kHz per-phase operation. The MAX8707 is available in the low-profile, 40-pin, 6mm x 6mm thin QFN package. Refer to the MAX8702/MAX8703 for compatible drivers.