1
ISL6530
Dual 5V Synchronous Buck Pulse-Width
Modulator (PWM) Controller for DDRAM
Memory V
DDQ
and V
TT
Termination
The ISL6530 provides complete control and protection for
dual DC-DC converters optimized for high-performance
DDRAM memory applications. It is designed to drive low
cost N-channel MOSFETs in synchronous-rectified buck
topology to efficiently generate 2.5V V
DDQ
for powering
DDRAM memory, V
REF
for DDRAM differential signalling,
and V
TT
for signal termination. The ISL6530 integrates all of
the control, output adjustment, monitoring and protection
functions into a single package.
The V
DDQ
output of the converter is maintained at 2.5V
through an integrated precision voltage reference. The V
REF
output is precisely regulated to 1/2 the memory power
supply, with a maximum tolerance of 1% over temperature
and line voltage variations. V
TT
accurately tracks V
REF
.
During V2_SD sleep mode, the V
TT
output is maintained by
a low power window regulator.
The ISL6530 provides simple, single feedback loop, voltage-
mode control with fast transient response. It includes two
phase-locked 300kHz triangle-wave oscillators which are
displaced 90
o
to minimize interference between the two
PWM regulators. The regulators feature error amplifiers with
a 15MHz gain-bandwidth product and 6V/s slew rate which
enables high converter bandwidth for fast transient
performance. The resulting PWM duty ratio ranges from 0%
to 100%.
The ISL6530 protects against over-current conditions by
inhibiting PWM operation. The ISL6530 monitors the current
in the V
DDQ
regulator by using the r
DS(ON)
of the upper
MOSFET which eliminates the need for a current sensing
resistor.
Ordering Information
Features
• Provides V
DDQ
, V
REF
, and V
TT
voltages for one- and two-
channel DDRAM memory systems
• Excellent voltage regulation
-V
DDQ
= 2.5V 2% over full operating range
-V
REF
= (V
DDQ
2) 1% over full operating range
-V
TT
= V
REF
30mV
• Supports ‘S3’ sleep mode
-V
TT
is held at V
DDQ
2 via low power window regulator
to minimize wake-up time
• Fast transient response
- Full 0% to 100% duty ratio
• Operates from +5V input
• Overcurrent fault monitor on VDD
- Does not require extra current sensing element
- Uses MOSFET’s r
DS(ON)
• Drives inexpensive N-Channel MOSFETs
• Small converter size
- 300kHz fixed frequency oscillator
• 24 Lead, SOIC or 32 Lead, 5mm5mm QFN
• Pb-Free Available (RoHS Compliant)
Applications
•V
DDQ
, V
TT
, and VREF regulation for DDRAM memory
systems
- Main Memory in AMD® Athlon™ and K8™, Pentium®
III, Pentium IV, Transmeta, PowerPC™, AlphaPC™,
and UltraSparc® based computer systems
- Video memory in graphics systems
• High-power tracking DC-DC regulators
PART NUMBER
TEMP
RANGE(
o
C) PACKAGE
PKG.
DWG. #
ISL6530CB* 0 to 70 24 Lead SOIC M24.3
ISL6530CBZ*
(See Note)
0 to 70 24 Lead SOIC
(Pb-free)
M24.3
ISL6530CR* 0 to 70 32 Lead 5x5 QFN L32.5x5
ISL6530CRZ*
(See Note)
0 to 70 32 Lead 5x5 QFN
(Pb-free)
L32.5x5
ISL6530EVAL1, 2 Evaluation Board
* Add “-T” suffix for tape and reel option.
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-020C.
Data Sheet November 15, 2004 FN9052.2
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. 2003, 2004. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
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