ISL6537
®
Data Sheet
February 8, 2005
FN9142.4
ACPI Regulator/Controller for
Features
• Generates 4 Regulated Voltages
Dual Channel DDR Memory Systems
The ISL6537 provides a complete ACPI compliant power
solution for up to 4 DIMM dual channel DDR/DDR2 Memory
systems. Included are both a synchronous buck controller to
- Synchronous Buck PWM Controller for DDR V
DDQ
- 3A Integrated Sink/Source Linear Regulator with
Accurate VDDQ/2 Divider Reference for DDR V
- LDO Regulator for GMCH Core
TT
supply V
during S0/S1 and S3 states. During S0/S1
DDQ
state, a fully integrated sink-source regulator generates an
accurate (V /2) high current V voltage without the
- LDO Regulator for CPU/GMCH V Termination
TT
DDQ TT
• ACPI compliant sleep state control
need for a negative supply. A buffered version of the V
/2
DDQ
reference is provided as V
. Two LDO controllers are also
• Glitch-free Transitions During State Changes
REF
integrated for the GMCH core voltage regulation and for the
• Integrated V
Buffer
REF
GMCH and CPU V termination voltage regulation.
TT
• PWM Controller Drives Low Cost N-Channel MOSFETs
The switching PWM controller drives two N-Channel
MOSFETs in a synchronous-rectified buck converter
topology. The synchronous buck converter uses voltage-
mode control with fast transient response. The switching
regulator provides a maximum static regulation tolerance of
±2% over line, load, and temperature ranges. The output is
user-adjustable by means of external resistors down to 0.8V.
• 250kHz Constant Frequency Operation
• Tight Output Voltage Regulation
- All Outputs: ±2% Over Temperature
• Fully-Adjustable Outputs with Wide Voltage Range: Down
to 0.8V supports DDR and DDR2 Specifications
• Simple Single-Loop Voltage-Mode PWM Control Design
• Fast PWM Converter Transient Response
An integrated soft-start feature brings all outputs into
regulation in a controlled manner when returning to S0/S1
state from any sleep state. During S0 the VIDPGD signal
• Under and Over-voltage Monitoring on All Outputs
• OCP on the Switching Regulator
indicates that the GMCH and CPU V termination voltage
TT
is within spec and operational.
• Integrated Thermal Shutdown Protection
• Pb-Free Available (RoHS Compliant)
Each output is monitored for undervoltage events. The
switching regulator also has overvoltage and over current
protection. Thermal shutdown is integrated.
Applications
•
Single and Dual Channel DDR Memory Power Systems in
ACPI compliant PCs
Pinout
ISL6537 (6x6 QFN)
TOP VIEW
•
Graphics cards - GPU and memory supplies
• ASIC power supplies
• Embedded processor and I/O supplies
• DSP supplies
28 27 26 25 24 23 22
5VSBY
S3#
1
2
3
4
5
6
7
21 DRIVE4
20
19
REFADJ4
DRIVE3
Ordering Information
P12V
TEMP. RANGE
PKG.
PART NUMBER
(°C)
PACKAGE
DWG. #
GND
29
GND
18 FB3
17
ISL6537CR
0 to 70
0 to 70
28 Ld 6x6 QFN L28.6x6
DDR_VTT
DDR_VTT
VDDQ
FB4
ISL6537CRZ
(See Note)
28 Ld 6x6 QFN L28.6x6
(Pb-free)
16 COMP
15 FB
*Add “-T” suffix to part number for tape and reel packaging.
8
9
10
11 12 13 14
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-020.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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1
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