1

®

ISL6540

Data Sheet

July 23, 2008

FN9214.1

Single-Phase Buck PWM Controller with

Integrated High Speed MOSFET Driver

and Pre-Biased Load Capability

The ISL6540 is a single-phase voltage-mode PWM controller

with input voltage feedforward compensation to maintain a

constant loop gain for optimal transient response, especially for

applications with a wide input voltage range. Its integrated high

speed synchronous rectified MOSFET drivers and other

sophisticated features provide complete control and protection

for a DC/DC converter with minimum external components,

resulting in minimum cost and less engineering design efforts.

The output voltage of the converter can be precisely regulated

with an internal reference voltage of 0.591V, and has a system

tolerance of ±0.85% over commercial temperature and line load

variations. An external voltage can be used in place of the

internal reference for voltage tracking/DDR applications.

The ISL6540 has an internal linear regulator or external linear

regulator drive options for applications with only a single supply

rail. The internal oscillator is adjustable from 250kHz to 2MHz.

The integrated voltage margining, programmable pre-biased

soft-start, differential remote sensing amplifier, and

programmable input voltage POR features enhance the

ISL6540 value.

Pinout

ISL6540

(28 LD 5x5 QFN)

TOP VIEW

Features

• VIN and Power Rail Operation from +3.3V to +20V

• Fast Transient Response - 0 to 100% Duty Cycle

-

15MHz Bandwidth Error Amplifier with 6V/μs Slew Rate

- Voltage-Mode PWM Leading and Trailing-edge

Modulation Control

- Input Voltage Feedforward Compensation

• 2.9V to 5.6V High Speed 2A/4A MOSFET Gate Drivers

-

Tri-state for Power Stage Shutdown

•

Internal Linear Regulator (LR) - 5.6V Bias from VIN

•

External LR Drive for Optimal Thermal Performance

• Voltage Margining with Independently Adjustable Upper and

Lower Settings for System Stress Testing & Over Clocking

•

Reference Voltage I/O for DDR/Tracking Applications

•

Precise 0.591V Internal Reference with Buffered Output

-

±0.85%/±1.25% Over Commercial/Industrial Range

•

Source and Sink Overcurrent Protections

-

Low- and High-Side MOSFET rDS(ON) Sensing

•

Overvoltage and Undervoltage Protections

•

Small Converter Size - QFN package

• Oscillator Programmable from 250kHz to 2MHz

• Differential Remote Voltage Sensing with Unity Gain

• Programmable Soft-start with Pre-Biased Load Capability

• Power Good Indication with Programmable Delay

• EN Input with Voltage Monitoring Capability

• Pb-Free Plus Anneal Available (RoHS Compliant)

Applications

•

Power Supply for some Microprocessors and GPUs

•

Wide and Narrow Input Voltage Range Buck Regulators

•

Point of Load Applications

•

Low-Voltage and High Current Distributed Power Supplies

VSEN+

REFOUT

PHASE

BOOT

UGATE

PGND

VSEN-

LGATE

SS

OFS-

PVCC

LINDRV

OFS+

REFIN

1

2

3

4

5

6

7

21

20

19

18

17

16

15

28

27

26

25

24

23

22

8

9

10

11

12

13

14

GND

BOTTOM

SIDE PAD

Ordering Information

PART

NUMBER*

(Note)

PART

MARKING

TEMP.

RANGE (°C)

PACKAGE

(Pb-Free)

PKG.

DWG. #

ISL6540CRZ

ISL6540CRZ

0 to 70

28 Ld QFN L28.5x5

ISL6540CRZA ISL6540CRZ

0 to 70

28 Ld QFN L28.5x5

ISL6540IRZA

ISL6540IRZ

-40 to 85

28 Ld QFN L28.5x5

*Add “-T” suffix for tape and reel.

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.

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

| Intersil (and design) is a registered trademark of Intersil Americas Inc.

Copyright Intersil Americas Inc. 2006, 2008. All Rights Reserved

All other trademarks mentioned are the property of their respective owners.

NOT RE

COMME

NDED FO

R NEW D

ESIGNS

RECOMM

ENDED

REPLAC

EMENT

PART

ISL6540

A