Three-Phase PWM Controller Includes Power MOSFET Drivers

Milpitas, Calif. — Intersil Corp. unveiled the ISL6566, a three-phase pulse-width modulation (PWM) control IC, with integrated metal-oxide semiconductor field-effect transistor (MOSFET) drivers.

The ISL6566 provides a precision voltage regulation system and includes programmable voltage identification (VID) codes compatible with Intel Pentium 4 VRM9/ VRM10/10.1 and AMD Opteron and Athlon microprocessors.

The integration of power MOSFET drivers into the controller IC marks a departure from the separate PWM controller and driver configuration of previous multiphase product families. By integrating a number of external parts, in a near-chip-scale 6mm x 6mm QFN package, the ISL6566 reduces bill of materials (BOM) cost and printed-circuit board area, while providing compliance to the Intel and AMD CPU core specifications.

A unique feature of the ISL6566 is the all-in-one VID inputs. The ISL6566 can accept VID digital inputs from both Intel and AMD CPUs. This greatly simplifies the customers' logistics, as the ISL6566 becomes a single-chip solution on Intel Celeron and P4 processors (5xx, 6xx and Extreme Edition), and AMD Athlon, Athlon64 and Opteron platforms. Intersil's Dynamic-VID technology allows seamless on-the-fly voltage changes utilizing the VID bus. The offset pin allows accurate voltage offset settings that are independent of VID bus setting.

The ISL6566 also combines use of both direct-current resistance (DCR) and RDS(ON) current sensing. Load line voltage positioning (droop) and over-current protection are accomplished through continuous inductor DCR current sensing, while RDS(ON) current sensing is used for accurate channel-current balance. Using both methods of current sampling utilizes the best advantages of each technique. A unity gain, differential amplifier is provided for remote voltage sensing, compensating for any potential difference between remote and local grounds. The output voltage can also be positively or negatively offset through the use of a single external resistor. The adjustable switching frequency of up to 1.5 MHz/phase enables the system designer to optimize the conduction and switching losses in his/her design.

The ISL6566's 6mm x 6mm QFN package enables good thermal performance. At the bottom of the IC is a copper pad that can be directly connected to the printed-circuit board ground layer, facilitating easy transfer of heat from the switching regulator to the inner pcb copper layers.

Protection features of this controller IC include a set of sophisticated over-voltage, under-voltage, and over-current protection. Over-voltage results in the converter turning the lower MOSFETs ON to clamp the rising output voltage and protect the microprocessor. The over-current protection level is set through a single external resistor. The ISL6566 also includes protection against an open circuit on the remote sensing inputs. Combined, these features provide advanced protection for the microprocessor and power system.

ISL6566 Features

*1, 2 or 3 phase power conversion
*Precision core voltage regulation: Differential remote voltage sensing for tighter accuracy, ±0.5% system accuracy over temperature saves output caps, adjustable reference-voltage offset for loadline programming
*Precision channel current sensing: Uses loss-less RDS(ON) current sampling
*Accurate load line programming: Uses loss-less inductor DCR current sampling
*Variable gate drive bias: 5 V to 12 V
*Microprocessor voltage identification inputs: Up to 6-bit DAC, selectable between Intel's VRM9, VRM10 or AMD DAC codes, Dynamic VID technology
*Over-current protection and over-voltage protection
*Digital soft start
*Selectable operation frequency up to 1.5 MHz per phase

The ISL6566 is available now in Pb-free, 6mm x 6-mm QFN packaging. The suggested price in 10,000 unit quantities is $1.75 for each IC.

Additional information on these and other high-performance power solutions can be obtained online from Intersil's Power Web site at:

0 comments on “Three-Phase PWM Controller Includes Power MOSFET Drivers

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.