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ISL6548A Datasheet, PDF (1/16 Pages) Intersil Corporation – ACPI Regulator/Controller for Dual Channel DDR Memory Systems
®
PRELIMINARY
Data Sheet
July 22, 2005
ISL6548A
FN9189.1
ACPI Regulator/Controller for
Dual Channel DDR Memory Systems
The ISL6548A 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
supply VDDQ during S0/S1 and S3 states. During S0/S1
state, a fully integrated sink-source regulator generates an
accurate (VDDQ/2) high current VTT voltage without the
need for a negative supply. A second PWM controller, which
requires external MOSFET drivers, is available for regulation
of the GMCH Core voltage. A sink/source LDO controller is
also integrated for the CPU/GMCH VTT termination voltage
regulation. Another LDO is available for the ICH7 voltage.
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.
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
indicates that the GMCH and CPU VTT termination voltage
is within spec and operational.
All outputs, except VICH7, have undervoltage protection. The
switching regulator also has overvoltage and overcurrent
protection. Thermal shutdown is integrated.
Features
• Generates 5 Regulated Voltages
- Synchronous Buck PWM Controller for DDR VDDQ
- 3A Integrated Sink/Source Linear Regulator with
Accurate VDDQ/2 Divider Reference for DDR VTT
- PWM Regulator for GMCH Core
- Sink/Source LDO Regulator for CPU/GMCH VTT
Termination
- LDO Regulator for ICH7
• ACPI compliant sleep state control
• Glitch-free Transitions During State Changes
• VDDQ PWM Controller Drives Low Cost N-Channel
MOSFETs
• 250kHz Constant Frequency Operation
- Both PWM controllers are Phase Shifted 180°
• 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
• Under and Overvoltage Monitoring
• OCP on the VDDQ Switching Regulator
• Integrated Thermal Shutdown Protection
• Pb-Free Plus Anneal Available (RoHS Compliant)
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
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CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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