Multiphase, Fixed-Frequency Controller for AMD Hammer CPU Core Power Supplies
SUNNYVALE, CA-September 24, 2004-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX8707, a multiphase (2-/3-/4-phase), interleaved, fixed-frequency, step-down controller for AMD® Hammer CPU core power supplies. Interleaved multiphase operation reduces the input ripple current and output voltage ripple, thereby reducing the input and output capacitor requirements and saving cost. The MAX8707 includes active voltage positioning with adjustable gain and offset, which reduces power dissipation and bulk output-capacitance requirements.
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, two-stage conversion (stepping down the +5V system supply instead of the battery) at a higher switching frequency permits the smallest possible physical size.
The MAX8707 features dedicated differential current-sense inputs for each phase. Using a single current-sense resistor, a fifth pair of current-sense inputs provides an accurate voltage positioning slope and average current-limit protection. Two dedicated inputs provide differential remote-voltage sensing, and a selectable switching frequency allows 200kHz, 300kHz, or 600kHz per-phase operation.
The MAX8707 is available in a low-profile 40-pin, 6mm x 6mm, thin QFN package. (Refer to the MAX8702/MAX8703 for compatible drivers.)
The device is screened for the -40°C to +85°C temperature range. Prices start at $11.97 (1000-up, FOB USA).
AMD is a registered trademark of Advanced Micro Devices, Inc.
|
