1

Multiphase PWM Regulator for AMD Fusion™ Mobile

CPUs Using SVI 2.0

ISL6277

The ISL6277 is fully compliant with AMD Fusion™ SVI 2.0 and

provides a complete solution for microprocessor and graphics

processor core power. The ISL6277 controller supports two

Voltage Regulators (VRs) with three integrated gate drivers and

two optional external drivers for maximum flexibility. The Core VR

can be configured for 3-, 2-, or 1-phase operation while the

Northbridge VR supports 2- or 1-phase configurations. The two

VRs share a serial control bus to communicate with the AMD CPU

and achieve lower cost and smaller board area compared with

two-chip solutions.

The PWM modulator is based on Intersil’s Robust Ripple

Regulator R3 Technology™. Compared to traditional modulators,

the R3 modulator can automatically change switching frequency

for faster transient settling time during load transients and

improved light load efficiency.

The ISL6277 has several other key features. Both outputs

support DCR current sensing with single NTC thermistor for

DCR temperature compensation or accurate resistor current

sensing. Both outputs utilize remote voltage sense, adjustable

switching frequency, OC protection and power good.

Applications

• AMD Fusion CPU/GPU Core Power

• Notebook Computers

Features

• Supports AMD SVI 2.0 Serial Data Bus Interface

• Dual Output Controller with Integrated Drivers

- Two Dedicated Core Drivers

- One Programmable Driver for Either Core or Northbridge

• Precision Voltage Regulation

- 0.5% System Accuracy Over-Temperature

- 0.5V to 1.55V in 6.25mV Steps

- Enhanced Load Line Accuracy

• Supports Multiple Current Sensing Methods

- Lossless Inductor DCR Current Sensing

- Precision Resistor Current Sensing

• Programmable 1-, 2- or 3-Phase for the Core Output and

1- or 2-Phase for the Northbridge Output

• Adaptive Body Diode Conduction Time Reduction

• Superior Noise Immunity and Transient Response

• Output Current Monitor and Thermal Monitor

• Differential Remote Voltage Sensing

• High Efficiency Across Entire Load Range

•Programmable Slew Rate

• Programmable VID Offset and Droop on Both Outputs

• Programmable Switching Frequency for Both Outputs

• Excellent Dynamic Current Balance Between Phases

• OCP/WOC, OVP, PGOOD, and Thermal Monitor

• Small Footprint 48 Ld 6x6 QFN Package

- Pb-Free (RoHS Compliant)

Core Performance

FIGURE 1. EFFICIENCY vs LOAD

0

10

20

30

40

50

60

70

80

90

100

0

5

10 15 20 25 30 35 40 45 50 55

0.96

0.98

1.00

1.02

1.04

1.06

1.08

1.10

1.12

0

5

10 15 20 25 30 35 40 45 50 55

March 8, 2012

FN8270.1

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774

Intersil (and design) and R3 Technology are trademarks owned by Intersil Corporation or one of its subsidiaries.

All other trademarks mentioned are the property of their respective owners.