The ISL6217A Multi-Phase Buck PWM controller IC, with integrated half bridge gate drivers, provides a precision voltage regulation system for advanced Pentium IV microprocessors in notebook computers. Two-phase operation eases the thermal management issues and load demand of Intel's latest high performance processors. This control IC also features both input voltage feed-forward and average current mode control for excellent dynamic response, "Loss-less" current sensing using MOSFET rDS(ON) and user-selectable switching frequencies from 250kHz to 1MHz per phase.
The ISL6217A includes a 6-bit digital-to-analog converter (DAC) that dynamically adjusts the CORE PWM output voltage from 0.700V to 1.708V in 16mV steps and conforms to the Intel IMVP-IV™ and IMVP-IV+™ mobile VID specification. The ISL6217A also has logic inputs to select Active, Deep Sleep and Deeper Sleep modes of operation. A precision reference, remote sensing and proprietary architecture, with integrated, processor-mode, compensated "Droop", provide excellent static and dynamic CORE voltage regulation.
To improve efficiency at light loading, the ISL6217A can be configured to run in single phase PWM in ACTIVE, DEEP or DEEPER SLEEP modes of operation. Also, in deep and deeper sleep modes the ISL6217A will operate in diode emulation.
Another feature of this IC controller is the PGOOD monitor circuit that is held low until CORE voltage increases, during its soft-start sequence, to within 12% of the "Boot" voltage. This PGOOD signal is masked during VID changes. Output overcurrent, overvoltage and undervoltage are monitored and result in the converter latching off and PGOOD signal being held low.
The overvoltage and undervoltage thresholds are 112% and 84% of the VID, Deep or Deeper Sleep setpoint, respectively. Overcurrent protection features a 32 cycle overcurrent shutdown. PGOOD, overvoltage, undervoltage and overcurrent provide monitoring and protection for the microprocessor and power system. The ISL6217A IC is available in a 38 lead TSSOP. |
