The ISL9500 multi-phase Buck PWM control IC, with
integrated half bridge gate drivers, provides a precision
voltage regulation system for microprocessors in notebook
computers. Two-phase operation eases the thermal
management issues and load demand of 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 ISL9500 includes a 6-bit digital-to-analog converter
(DAC) that dynamically adjusts the CORE PWM output
voltage. The ISL9500 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 ISL9500 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 ISL9500 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 ISL9500 IC is
available in a 38 lead TSSOP.
Features
• Diode Emulation Functionality in Deep and Deeper Sleep
Modes for Improved Light Load Efficiency
• Single and/or Two-phase Power Conversion
• “Loss-less” Current sensing for Improved Efficiency and
Reduced Board Area
- Optional Discrete Precision Current Sense Resistor
• Internal Gate-Drive and Boot-Strap Diodes
• Precision CORE Voltage Regulation
- 0.8% System Accuracy Over Temperature
• 6-Bit Microprocessor Voltage Identification Input
• Programmable “Droop” and CORE Voltage Slew Rate
• Direct Interface with System Logic for Deep and Deeper
Sleep modes of operation
• Easily Programmable Voltage Setpoints for Initial “Boot”,
Deep Sleep and Deeper Sleep Modes
• Excellent Dynamic Response
- Combined Voltage Feed-Forward and Average Current
Mode Control
• Overvoltage, Undervoltage and Overcurrent Protection
• Power-Good Output with Internal Blanking during VID and
Mode Changes
• User programmable Switching Frequency of 250kHz -
1MHz
• Pb-Free Plus Anneal Available (RoHS Compliant)
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