
1
ACPI Regulator/Controller for
Dual Channel DDR Memory Systems
The ISL6532 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
and integrated LDO to supply V
DDQ
with high current during
S0/S1 states and standby current during S3 state. During
Run mode, a fully integrated sink-source regulator generates
an accurate (V
DDQ
/2) high current V
TT
voltage without the
need for a negative supply. A buffered version of the V
DDQ
/2
reference is provided as V
REF
.
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. Both the switching
regulator and integrated standby LDO provide 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.
Switching the memory core output between the PWM
regulator and the standby LDO during state transitions is
accomplished smoothly via the internal ACPI control
circuitry. The NCH signal provides synchronized switching of
a backfeed blocking switch during the transitions
eliminating
the need to route 5V Dual to the memory supply
.
An integrated soft-start feature brings V
DDQ
into regulation in
a controlled manner when returning to S0/S1 state from
S4/S5 or mechanical off states. During S0 the PGOOD signal
indicates that all supplies are within spec and operational.
Each output is monitored for under and over-voltage events.
Current limiting is included on the V
TT
and V
DDQ
standby
regulators. Thermal shutdown is integrated.
Pinout
ISL6532 (QFN)
TOP VIEW
Features
Generates 2 Regulated Voltages
- Synchronous Buck PWM Controller with Standby LDO
- 3A Integrated Sink/Source Linear Regulator with
Accurate V
DDQ
/2 Divider Reference.
- Glitch-free Transitions During State Changes
ACPI Compliant Sleep State Control
Integrated V
REF
Buffer
PWM Controller Drives Low Cost N-Channel MOSFETs
250kHz Constant Frequency Operation
Tight Output Voltage Regulation
- Both Outputs:
±
2% Over Temperature
5V or 3.3V Down Conversion
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
Over Current Protection and Under/Over-Voltage
Monitoring of Both Outputs
Integrated Thermal Shutdown Protection
QFN Package Option
- QFN Compliant to JEDEC PUB95 MO-220 QFN - Quad
Flat No Leads - Product Outline
- QFN Near Chip Scale Package Footprint; Improves
PCB Efficiency, Thinner in Profile
Pb-free available
Applications
Single and Dual Channel DDR Memory Power Systems in
ACPI compliant PCs
Graphics cards - GPU and memory supplies
ASIC power supplies
Embedded processor and I/O supplies
DSP supplies
NCH
PGOOD
GND
COMP
FB
5VSBY
GND
VTT
VTT
VDDQ
U
L
P
S
S
V
V
P
V
V
1
2
3
4
5
6
7
8
9
10
15
14
13
12
11
20
19
18
17
16
GND
21
Ordering Information
PART NUMBER
TEMP. RANGE
(
o
C)
PACKAGE
PKG.
DWG. #
ISL6532CR
0 to 70
20 Ld 6x6 QFN
L20.6x6
ISL6532CRZ
(See Note)
0 to 70
20 Ld 6x6 QFN
(Pb-free)
L20.6x6
*Add “-T” suffix to part number for tape and reel packaging.
NOTE: Intersil Pb-free products employ special Pb-free material sets; molding
compounds/die attach materials and 100% matte tin plate termination finish, which
is 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-020B.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2002-2004. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
ISL6532
July 2004
FN9112.3
Data Sheet