ISL6445 Datasheet, PDF (1/15 Pages) Intersil Corporation – 1.4MHz Dual, 180 Out-of-Phase, Step-Down PWM Controller

®
Data Sheet
June 3, 2008
ISL6445
FN9230.1
1.4MHz Dual, 180° Out-of-Phase,
Step-Down PWM Controller
The ISL6445 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 ISL6445 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
ISL6445
(24 LD QSOP)
TOP VIEW
LGATE2 1
BOOT2 2
UGATE2 3
PHASE2 4
ISEN2 5
PGOOD 6
VCC5 7
SD2 8
SS2 9
OCSET2 10
FB2 11
VIN 12
24 LGATE1
23 BOOT1
22 UGATE1
21 PHASE1
20 ISEN1
19 PGND
18 SD1
17 SS1
16 SGND
15 OCSET1
14 FB1
13 BIAS
Features
• Wide Input Supply Voltage Range
- 5.6V to 24V
- 4.5V to 5.6V
• Two Independently Programmable Output Voltages
• Switching Frequency . . . . . . . . . . . . . . . . . . . . . . .1.4MHz
• 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
- Over-temperature
- Independent Shutdown for Both PWMs
• Excellent Dynamic Response
- Voltage Feed-Forward with Current Mode Control
• Pb-Free (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
Ordering Information
PART
NUMBER
(Note)
PART
TEMP.
PACKAGE PKG.
MARKING RANGE (°C) (Pb-Free) DWG. #
ISL6445IAZ* ISL 6445IAZ -40 to +85 24 Ld QSOP M24.15
*Add “-TK” suffix for tape and reel. Please refer to TB347 for details
on reel specifications.
NOTE: These Intersil Pb-free plastic packaged products employ
special Pb-free material sets, molding compounds/die attach
materials, and 100% matte tin plate plus anneal (e3 termination
finish, which is 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.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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