ISL6232 Datasheet, PDF (1/25 Pages) Intersil Corporation – High Efficiency System Power Supply Controller for Notebook Computers

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Data Sheet
April 20, 2009
ISL6232
FN9116.1
High Efficiency System Power Supply
Controller for Notebook Computers
The ISL6232 is a high efficiency, quad output controller
optimized for converting battery, wall adapter or network DC
input voltage into system supply voltages required for
portable applications. The ISL6232 includes two PWM
controllers generating 0.8V to 5.5V, or fixed 5V and 3.3V
outputs. It also features 5V and 3.3V always linear regulators
with up to 100mA output current.
ISL6232 uses constant frequency current mode PWM
control with out-of-phase operation for reducing the input
ripple current and the ESR requirement of the input
capacitors. Over 95% efficiency is achieved through
synchronous rectification and dual PWM/Skip mode
architecture. High light load efficiency with skip mode
extends the battery life in system standby or shutdown
mode. The 5V and 3.3V always linear regulators take their
inputs from battery or AC-adapter; and, to further improve
efficiency, their outputs are switched to the 5V or 3.3V
outputs from switching regulators when 5V or 3.3V is
available. Ultrasonic pulse skipping mode maintains
switching frequency above 25kHz to eliminate the audio
noise for high light load efficiency, and fixed frequency PWM
operation mode reduces the RF interference in sensitive
applications. External loop compensation is used to optimize
the transient response with optimized external components.
An accurate current sensing resistor in series with an output
inductor, or DC resistance of the inductor is used to sense
the output current of the current ramp signal, and
overcurrent protection. A peak current detecting scheme is
used for overcurrent protection and to prevent the inductor
from saturation.
The ISL6232 has internal soft-start to control the inrush
current. The soft-stop feature avoids negative output voltage
for undervoltage protection, overcurrent protection, and
shutdown by discharging output through an internal switch,
and by damping the inductor current. The ISL6232 also
features overvoltage protection, power-up sequences, power
good output, and thermal shutdown. It has quiescent power
dissipation as low as 3.5mW.
Features
• Supply Voltage Range: 5.5V to 25V
• 3.3V and 5V Fixed or Adjustable Outputs from 0.8V to
5.5V
• 5V, 3.3V/100mA Always Linear Regulators
• Out-of-Phase Operation Reduces the ESR Requirement
of the Input Capacitors
• ±1.5% Output Voltage Accuracy Over Temperature
• Fixed 300kHz Current Mode Control Architecture
• Accurate Current Sensing or DCR Current Sensing
• Internal Soft-Start and Soft-Stop Output Discharge
• Selectable Power-up Sequence
• Selectable Forced PWM, Pulse Skipping, and Ultrasonic
Pulse Skipping Mode (25kHz min)
• Peak Overcurrent Limit Prevents Inductor Saturation
• Overvoltage Protection, Undervoltage Shutdown
• Power Good Output
• Thermal shutdown
• 5µA Shutdown Current
• Integrated Bootstrap Schottky Diodes
• 3.5mW Quiescent Power Dissipation
• Pb-Free Available (RoHS Compliant)
Applications
• Notebook, Sub-notebook, and Tablet Computers
• 2- to 4-cell Li-ion Battery-Powered Devices
• Dual Output Supplies for DSP, Memory, Logic and
Microprocessor
• Telecom Systems, Network servers, and Storage
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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