1
®
FN9040.2
ISL6440
300kHz Dual, 180°
Out-of-Phase, Step-
Down PWM Controller
The ISL6440 is a high-performance, dual-output PWM
controller optimized for converting wall adapter, battery or
network intermediate bus DC input supplies into the system
supply voltages required for a wide variety of applications.
Each output is adjustable down to 0.8V. The two PWMs are
synchronized 180
o
out of phase reducing the RMS input
current and ripple voltage.
The ISL6440 incorporates several protection features. An
adjustable overcurrent protection circuit monitors the output
current by sensing the voltage drop across the lower
MOSFET. Hiccup mode overcurrent operation protects the
DC/DC components from damage during output
overload/short circuit conditions. Each PWM has an
independent logic-level shutdown input (SD1
and SD2).
A single PGOOD signal is issued when soft-start is complete
on both PWM controllers and their outputs are within 10% of
the set point. Thermal shutdown circuitry turns off the device
if the junction temperature exceeds +150°C.
Pinout
ISL6440 (QSOP)
TOP VIEW
Features
• Wide Input Supply Voltage Range
- 5.6V to 24V
- 4.5V to 5.6V
• Two Independently Programmable Output Voltages
• Switching Frequency . . . . . . . . . . . . . . . . . . . . . . . 300kHz
• Out of Phase PWM Controller Operation
- Reduces Required Input Capacitance and Power
Supply Induced Loads
• No External Current Sense Resistor
- Uses Lower MOSFET’s r
DS(ON)
• Programmable Soft-Start
• Extensive Circuit Protection Functions
- PGOOD
-UVLO
- Overcurrent
- Overtemperature
- Independent Shutdown for Both PWMs
• Excellent Dynamic Response
- Voltage Feed-Forward with Current Mode Control
• Pb-Free Plus Anneal Available (RoHS Compliant)
Applications
• Power Supplies with Two Outputs
• xDSL Modems/Routers
• DSP, ASIC, and FPGA Power Supplies
• Set-Top Boxes
• Dual Output Supplies for DSP, Memory, Logic, µP Core
and I/O
• Telecom Systems
1
2
3
4
5
6
7
8
9
10
11
12
16
17
18
19
20
21
22
23
24
15
14
13
LGATE2
BOOT2
UGATE2
PHASE2
ISEN2
PGOOD
VCC5
SD2
SS2
OCSET2
FB2
VIN
LGATE1
UGATE1
PHASE1
ISEN1
PGND
SS1
OCSET1
FB1
BIAS
BOOT1
SD1
SGND
Ordering Information
PART
NUMBER
PART
MARKING
TEMP.
RANGE
(°C) PACKAGE
PKG.
DWG. #
ISL6440IA ISL6440IA -40 to 85 24 Ld QSOP M24.15
ISL6440IAZ
(See Note)
ISL6440IAZ -40 to 85 24 Ld QSOP
(Pb-free)
M24.15
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material
sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with both SnPb
and Pb-free soldering operations. Intersil Pb-free products are MSL classified
at Pb-free peak reflow temperatures that meet or exceed the Pb-free
requirements of IPC/JEDEC J STD-020.
Add “-T” or “-TK” suffix for tape and reel.
Data Sheet October 4, 2005
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
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Copyright © Intersil Americas Inc. 2005. All Rights Reserved
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