ISL6237 Datasheet, PDF (1/35 Pages) Intersil Corporation – High-Efficiency, Quad-Output, Main Power Supply Controllers for Notebook Computers

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Data Sheet
March 18, 2008
ISL6237
FN6418.4
High-Efficiency, Quad-Output, Main Power
Supply Controllers for Notebook
Computers
The ISL6237 dual step-down, switch-mode power-supply
(SMPS) controller generates logic-supply voltages in
battery-powered systems. The ISL6237 includes two
pulse-width modulation (PWM) controllers, 5V/3.3V and
1.5V/1.05V. The output of SMPS1 can also be adjusted from
0.7V to 5.5V. The SMPS2 output can be adjusted from 0.5V to
2.5V by setting REFIN2 voltage. This device features a linear
regulator providing 3.3V/5V, or adjustable from 0.7V to 4.5V
output via LDOREFIN. The linear regulator provides up to
100mA output current with automatic linear-regulator
bootstrapping to the BYP input. When in switchover, the LDO
output can source up to 200mA. The ISL6237 includes
on-board power-up sequencing, power-good (POK_) outputs,
digital soft-start, and internal soft-stop output discharge that
prevents negative voltages on shutdown.
Constant on-time PWM control scheme operates without
sense resistors and provides 100ns response to load
transients while maintaining a relatively constant switching
frequency. The unique ultrasonic pulse-skipping mode
maintains the switching frequency above 25kHz, which
eliminates noise in audio applications. Other features include
pulse skipping, which maximizes efficiency in light-load
applications, and fixed-frequency PWM mode, which reduces
RF interference in sensitive applications.
Ordering Information
PART
NUMBER
(Note)
PART
MARKING
TEMP.
RANGE
(°C)
PACKAGE PKG.
(Pb-free) DWG. #
ISL6237IRZ ISL6237 IRZ -40 to +100 32 Ld 5x5 QFN L32.5x5B
ISL6237IRZ-T* ISL6237 IRZ -40 to +100 32 Ld 5x5 QFN L32.5x5B
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.
Features
• Wide Input Voltage Range 5.5V to 25V
• Dual Fixed 1.05V/3.3V and 1.5V/5.0V Outputs or
Adjustable 0.7V to 5.5V (SMPS1) and 0.5V to 2.5V
(SMPS2), ±1.5% Accuracy
• 1.7ms Digital Soft-Start and Independent Shutdown
• Fixed 3.3V/5.0V, or Adjustable Output 0.7V to 4.5V,
±1.5% (LDO): 200mA
• 2.0V Reference Voltage
• Constant ON-TIME Control with 100ns Load-Step
Response
• Selectable Switching Frequency
• r_DS(ON) Current Sensing
• Programmable Current Limit with Foldback Capability
• Selectable PWM, Skip or Ultrasonic Mode
• BOOT Voltage Monitor with Automatic Refresh
• Independent POK1 and POK2 Comparators
• Soft-Start with Pre-Biased Output and Soft-Stop
• Independent ENABLE
• High Efficiency - Up to 97%
• Very High Light Load Efficiency (Skip Mode)
• 5mW Quiescent Power Dissipation
• Thermal Shutdown
• Extremely Low Components Count
• Pb-Free (RoHS Compliant)
Applications
• Notebook and Sub-Notebook Computers
• PDAs and Mobile Communication Devices
• 3-Cell and 4-Cell Li+ Battery-Powered Devices
• DDR1, DDR2, and DDR3 Power Supplies
• Graphic Cards
• Game Consoles
• Telecommunication
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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