ISL9440 Datasheet, PDF (1/20 Pages) Intersil Corporation – Triple, 180° Out-of-Phase, Step-Down PWM and Single Linear Controller

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Data Sheet
ISL9440, ISL9440A, ISL9441
December 5, 2007
FN6383.1
Triple, 180° Out-of-Phase, Step-Down
PWM and Single Linear Controller
The ISL9440, ISL9440A and ISL9441 are quad-output
synchronous buck controllers that integrate 3 PWM
controllers and 1 low drop-out linear regulator controller, which
are full featured and designed to provide multi-rail power for
use in products such as cable and satellite set-top boxes,
VoIP gateways, cable modems, and other home connectivity
products as well as a variety of industrial and general purpose
applications. Each output is adjustable down to 0.8V. The
PWMs are synchronized at 180° out of phase thus reducing
the RMS input current and ripple voltage.
The ISL9440, ISL9440A and ISL9441 offer internal soft-start,
independent enable inputs for ease of supply rail
sequencing, and integrated UV/OV/OC/OT protections in a
space conscious 5mmx5mm QFN package. The ISL9440
and ISL9440A offer an early warning function to output a
logic signal to warn the system to back up data when input
voltage falls below a certain level.
The ISL9440, ISL9440A and ISL9441 utilize internal loop
compensation to keep minimum peripheral components for
compact design and a low total solution cost. These devices
are implemented with current mode control with feed forward
to cover various applications even with fixed internal
compensations.
The table below shows the difference in terms of ISL9440,
ISL9440A and ISL9441 features.
PART
NUMBER
ISL9440
ISL9440A
ISL9441
EARLY
WARNING
YES
YES
NO
SWITCHING FREQUENCY
(kHz)
300
600
300
Features
• Three Integrated Synchronous Buck PWM Controllers
- Internal Bootstrap Diodes
- Internal Compensation
- Internal Soft-Start
• Independent Control for Each Regulator and
Programmable Output Voltages; Independent
Enable/Shutdown
• Fixed Switching Frequency: 300kHz (ISL9440, ISL9441);
600kHz (ISL9440A)
• Adaptive Shoot Through Protection on all Synchronous
Buck Controllers
• Independently Programmable Voltage Outputs
• Out-of-Phase Switching to Reduce Input Capacitance
(0°/180°/0°)
• No External Current Sense Resistor
- Uses Lower MOSFET’s r_DS(ON)
• Current Mode Controller with Voltage Feed Forward
• Complete Protection
- Overcurrent, Overvoltage, Undervoltage Lockout,
Over-Temperature
• Cycle by Cycle Current Limiting
• Wide Input Voltage Range
- Input Rail Powers VIN Pin: 5.6V to 24V
- Input Rail Powers VCC_5V Pin (VIN tied to VCC_5V, for
5V input applications): 4.5V to 5.6V
• Early Warning (ISL9440, ISL9440A) on Input Voltage
Failure
• Integrated Reset Function (ISL9440, ISL9440A)
• Pb-free (RoHS compliant)
Applications
• Satellite and Cable Set-Top Boxes
• Cable Modems
• VoX Gateway Devices
• NAS/SAN Devices
Related Literature
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN (MLFP) Packages”
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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