ISL6224

Features:

• Adjustable output voltgage: 0.9-5.5V
• High efficiency over wide load range
- Higher efficiency in hysteretic mode at light load
• Lossless current sense scheme
- Uses MOSFET's rDS(ON)
- Optional current sense method higher precision
• Supply operation mode
- Wide VIN range: 4V-24V
- Single 5V system rail
• Input undervoltage lock-out on VCC pin(UVLO)
• Excellent dynamic response
- Combined voltage feed-forward and current mode
control
• Power-Good indicator
• 300/600kHz switching frequency
• Thermal shut-down
• Pb-Free Available (RoHS Compliant)


Application

• Mobile PCs
• Graphic cards
• Hand-held portable instruments


Pinout




Specifications

Bias Voltage, VCC. . . . . . . . . . . . . . . . . . .  . . . . . . . . . -0.3V to +7V
Input Voltage, Vin  . . . . . . . . . . . . . . . .  . .  . . . . . . . . . . . . . +27.0V
Phase and Isen Pins . . . . . . . . . . . . . . . . .. . . .GND -0.3V to +29.0V
BOOT and Ugate Pins  . . . . . . . . . . . . . . . . . . .. . . . . . . . . .  + 32.0V
BOOT with respect to PHASE . . . . . . . . . . . . . . .  . . . . . . . . . .+ 7.0V
All other pins  . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND -0.3V to 15V
ESD Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Class 2


Description

The ISL6224 provides power control and protection for a single,  adjustable output voltage required to power chip-sets and  memory banks in high-performance notebooks and PDAs. This  output voltage is adjustable in the range from 0.9-5.5V.

The hysteretic or PWM controller regulates the output  voltage from battery voltages ranging from 4V to 24V.
Synchronous rectification and hysteretic operation at light  loads contribute to a high efficiency over a wide range of
input voltages and loads. Efficiency is even further enhanced  by using MOSFET's rDS(ON) as a current sense component.  Feed-forward ramp modulation, average current mode  control and internal feed-back compensation provide fast  and firm handling of transients when powering advanced  chip sets.

Two-stage conversion using system 5V voltage is possible at  a higher frequency (600kHz) to minimize the output filter size.

The ISL6224 monitors the output voltage. A PGOOD (power  good) signal is issued when soft-start is completed and the  output is within ±10% of the set point.

A built-in overvoltage protection prevents output voltage  from going above 120% of the set point. Undervoltage
protection latches the chip off when the output drops below  70% of its setting value after soft-start sequence is
completed. The PWM controller's overcurrent circuitry  monitors the output current by sensing the voltage drop
across the lower MOSFET. If higher precision sense  technique is required, an optional external current-sense
resistor may be used.