1

®

FN9187.4

ISL6568

Two-Phase Buck PWM Controller with

Integrated MOSFET Drivers for VRM9,

VRM10, and AMD Hammer Applications

The ISL6568 two-phase PWM control IC provides a

precision voltage regulation system for advanced

microprocessors. The integration of power MOSFET drivers

into the controller IC marks a departure from the separate

PWM controller and driver configuration of previous multi-

phase product families. By reducing the number of external

parts, this integration is optimized for a cost and space

saving power management solution.

Outstanding features of this controller IC include

programmable VID codes compatible with Intel

VRM9,VRM10, as well as AMD Hammer microprocessors. A

unity gain, differential amplifier is provided for remote voltage

sensing, compensating for any potential difference between

remote and local grounds. The output voltage can also be

positively or negatively offset through the use of a single

external resistor.

A unique feature of the ISL6568 is the combined use of both

positioning (droop) and overcurrent protection are

accomplished through continuous inductor DCR current

channel-current balance. Using both methods of current

sampling utilizes the best advantages of each technique.

Protection features of this controller IC include a set of

sophisticated overvoltage, undervoltage, and overcurrent

protection. Overvoltage results in the converter turning the

lower MOSFETs ON to clamp the rising output voltage and

protect the microprocessor. The overcurrent protection level

is set through a single external resistor. Furthermore, the

ISL6568 includes protection against an open circuit on the

remote sensing inputs. Combined, these features provide

advanced protection for the microprocessor and power

system.

Features

• Integrated Multi-Phase Power Conversion

- 1 or 2-Phase Operation

• Precision Core Voltage Regulation

- Differential Remote Voltage Sensing

-

±0.5% System Accuracy Over Temperature

- Adjustable Reference-Voltage Offset

• Precision Channel Current Sharing

• Accurate Load Line Programming

- Uses Loss-Less Inductor DCR Current Sampling

• Variable Gate Drive Bias: 5V to 12V

• Microprocessor Voltage Identification Inputs

- Up to a 6-Bit DAC

- Selectable between Intel’s VRM9, VRM10, or AMD

Hammer DAC codes

- Dynamic VID-on-the-fly Technology

• Overcurrent Protection

• Multi-tiered Overvoltage Protection

• Digital Soft-Start

• Selectable Operation Frequency up to 1.5MHz Per Phase

• Pb-Free Plus Anneal Available (RoHS Compliant)

Pinout

ISL6568 (QFN)

TOP VIEW

PHASE1

VID4

VID3

PHASE2

BOOT2

BOOT1

ENLL

UGATE2

REF

OFS

VCC

FB

VDIFF

VID12.5

COMP

RGND

1

2

3

4

5

6

7

8

24

23

22

21

20

19

18

17

32

31

30

29

28

27

26

25

9

1011

12

13

1415

16

33

GND

Data Sheet

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

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March 9, 2006