ISL6540A
®
Data Sheet
March 12, 2007
FN6288.2
Single-Phase Buck PWM Controller with
Integrated High Speed MOSFET Driver
and Pre-Biased Load Capability
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
The ISL6540A is an improved version of the ISL6540
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.
- 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 & Over Clocking
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.
• 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
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.
• 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)
Pinout
ISL6540A
(28 LD 5x5 QFN)
TOP VIEW
Applications
• Power Supply for some Microprocessors and GPUs
• Wide and Narrow Input Voltage Range Buck Regulators
• Point of Load Applications
28 27 26 25 24 23 22
• Low-Voltage and High Current Distributed Power Supplies
VSEN+
1
2
3
4
5
6
7
21 BOOT
20 UGATE
19 PHASE
Ordering Information
VSEN-
REFOUT
REFIN
SS
PART
NUMBER*
(Note)
TEMP.
RANGE
(°C)
PART
MARKING
PACKAGE
(Pb-Free)
PKG.
DWG. #
GND
PGND
LGATE
PVCC
18
17
16
15
BOTTOM
SIDE PAD
ISL6540ACRZ ISL6540ACRZ 0 to +70 28 Ld 5x5 QFN L28.5x5
ISL6540ACRZA ISL6540ACRZ 0 to +70 28 Ld 5x5 QFN L28.5x5
OFS+
ISL6540AIRZ
ISL6540AIRZ -40 to +85 28 Ld 5x5 QFN L28.5x5
ISL6540AIRZA ISL6540AIRZ -40 to +85 28 Ld 5x5 QFN L28.5x5
LINDRV
OFS-
*Add “-T” suffix for tape and reel.
8
9
10 11 12 13 14
NOTE: Intersil Pb-free plus anneal 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-020.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1
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