ISL9440, ISL9440A, ISL9441
Data Sheet
February 9, 2015
FN6383.2
Triple, 180° Out-of-Phase, Step-Down
PWM and Single Linear Controller
Features
• Three integrated synchronous buck PWM controllers
- Internal bootstrap diodes
The ISL9440, ISL9440A and ISL9441 are quad-output
synchronous buck controllers that integrate 3 PWM
- Internal compensation
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.
- 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
The ISL9440, ISL9440A and ISL9441 offer internal soft-start,
independent enable inputs for ease of supply rail
• Independently programmable voltage outputs
• Out-of-phase switching to reduce input capacitance
(0°/180°/0°)
sequencing, and integrated UV/OV/OC/OT protections in a
space conscious 5mmx5mm QFN package. The ISL9440
and ISL9440A offers an early warning function to output a
logic signal to warn the system to back up data when the
input voltage falls below a certain level.
• No external current sense resistor
- Uses lower MOSFET’s rDS(ON)
• Current mode controller with voltage feed forward
The ISL9440, ISL9440A and ISL9441 are 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.
• 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
The table below shows the difference in terms of the
ISL9440, ISL9440A and ISL9441 features.
- Input rail powers VCC_5V Pin (VIN tied to VCC_5V, for
5V input applications): 4.5V to 5.6V
PART
NUMBER
EARLY
WARNING
SWITCHING FREQUENCY
(kHz)
• Early warning (ISL9440, ISL9440A) on input voltage
failure
ISL9440
YES
YES
NO
300
600
300
• Integrated reset function (ISL9440, ISL9440A)
• Pb-free (RoHS compliant)
ISL9440A
ISL9441
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”
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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