1
FN9148.2
ISL6521
PWM Buck DC-DC and Triple Linear
Power Controller
The ISL6521 provides the power control and protection for
four output voltages in low-voltage, high-performance
applications. The IC integrates a voltage-mode PWM
controller and three linear controllers, as well as monitoring
and protection functions into a 16-lead SOIC package. The
PWM controller is intended to regulate the low voltage
supply that requires the greatest amount of current (usually
the core voltage for the FPGA, ASIC, or processor) with a
synchronous rectified buck converter. The linears are
intended to regulate other system voltages, such as I/O
(input/output) and memory circuits. Both the switching
regulator and linear voltage reference provide 2% of static
regulation over line, load, and temperature ranges. All
outputs are user-adjustable by means of an external resistor
divider. All linear controllers can supply up to 120mA with no
external pass devices. Employing bipolar NPNs for the pass
transistors, the linear regulators can achieve output currents
of 3A or higher with proper device selection.
The ISL6521 monitors all the output voltages. The PWM
controller’s adjustable overcurrent function monitors the
output current by using the voltage drop across the upper
MOSFET’s r
DS(ON)
. The linear regulator outputs are
monitored via the FB pins for undervoltage events.
Features
• Provides 4 Regulated Voltages
- Switching Regulator 20A Capable
- Three Linear Regulators
- Capable of 120mA
- Capable of up to 3A with an External Transistor
• Externally Resistor-Adjustable Outputs
• Simple Single-Loop Control Design
- Voltage-Mode PWM Control
• Fast PWM Converter Transient Response
- High-Bandwidth Error Amplifier
- Full 0% to 100% Duty Ratio
• Excellent Output Voltage Regulation
- All Outputs: 2% Over Temperature
• Overcurrent Fault Monitors
- Switching Regulator Does Not Require Extra Current
Sensing Element, Uses MOSFET’s r
DS(ON)
• Small Converter Size
- 300kHz Constant Frequency Operation
- Small External Component Count
• Commercial and Industrial Temperature Range Support
• Pb-free Available (RoHS Compliant)
Applications
•
FPGA and
PowerPC
™
-based boards
• General purpose, low voltage power supplies
Related Literature
• Technical Support Document AG0001, “Power
Management Application Guide for Xilinx FPGAs”
• Technical Support Document AG0002, “Power
Management Application Guide for Altera FPGAs”
• Technical Support Document AG0005, “Power
Management Application Guide for Actel FPGAs”
Pinout
ISL6521 (SOIC)
TOP VIEW
Ordering Information
PART NUMBER TEMP. RANGE (°C) PACKAGE
PKG.
DWG. #
ISL6521CBZ
(Note)
0 to 70 16 Ld SOIC
(Pb-free)
M16.15
ISL6521CBZ-T
(Note)
0 to 70 16 Ld SOIC
(Pb-free)
M16.15
ISL6521IBZ
(Note)
-40 to 85 16 Ld SOIC
(Pb-free)
M16.15
ISL6521IBZ-T
(Note)
-40 to 85 16 Ld SOIC
(Pb-free)
M16.15
ISL6521EVAL1 Evaluation Board
NOTE: Intersil Pb-free 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-020C.
DRIVE2
FB2
FB
COMP
FB3
OCSET
DRIVE4
FB4
DRIVE3
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8UGATE
GND
LGATE
PHASE
BOOT
VCC
PGND
Data Sheet February 8, 2005
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
| Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas LLC. 2004. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
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