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)