1
®
ISL6540A
Data Sheet October 7, 2008 FN6288.5
Single-Phase Buck PWM Controller with
Integrated High Speed MOSFET Driver
and Pre-Biased Load Capability
The ISL6540A is an improved version of the ISL6540
single-phase voltage-mode PWM controller with input voltage
feed-forward 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 an
improved system tolerance of ±0.68% 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 ISL6540A 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
ISL6540A value.
Pinout
ISL6540A
(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 5.5V High Speed 2A/4A MOSFET Gate Drivers
- Tri-state for Power Stage Shutdown
• Internal Linear Regulator (LR) - 5.5V Bias from VIN
• External LR Drive for Optimal Thermal Performance
• Voltage Margining with Independently Adjustable Upper and
Lower Settings for System Stress Testing and Over Clocking
• Reference Voltage I/O for DDR/Tracking Applications
• Improved 0.591V Internal Reference with Buffered Output
- ±0.68%/±1.0% Over Commercial/Industrial Range
• Source and Sink Overcurrent Protections
- Low-and High-Side MOSFET r
DS(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 (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
MARCTRL
PG
EN
VMON
COMP
FS
PHASE
BOOT
UGATE
FB
PGND
PG_DLY
VCC
VSEN-
LGATE
GND
SS
OFS-
LSOC
HSOC
PVCC
LINDRV
VFF
VIN
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. #
ISL6540ACRZ* ISL6540 ACRZ 0 to +70 28 Ld 5x5 QFN L28.5x5
ISL6540AIRZ* ISL6540 AIRZ -40 to +85 28 Ld 5x5 QFN L28.5x5
ISL6540AIRZA* ISL6540 AIRZ -40 to +85 28 Ld 5x5 QFN L28.5x5
*Add “-T” suffix for tape and reel. Please refer to TB347 for details on
reel specifications.
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.
