FN9148 Rev 2.00

Page 1 of 14

Feb 8, 2005

FN9148

Rev 2.00

Feb 8, 2005

ISL6521

PWM Buck DC-DC and Triple Linear Power Controller

DATASHEET

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

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

• Small Converter Size

- 300kHz Constant Frequency Operation

- Small External Component Count

• Commercial and Industrial Temperature Range Support

• Pb-free Available (RoHS Compliant)

Applications

• 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

8

UGATE

GND

LGATE

PHASE

BOOT

VCC

PGND

NOT RECOMMENDED FOR NEW DESIGNS

NO RECOMMENDED REPLACEMENT

contact our Technical Support Center at

1-888-INTERSIL or www.intersil.com/tsc