FN4918 Rev 2.00

Page 1 of 18

July 2004

FN4918

Rev 2.00

July 2004

ISL6552

Microprocessor CORE Voltage Regulator Multi-Phase Buck PWM Controller

DATASHEET

The ISL6552 multi-phase PWM control IC together with its

companion gate drivers, the HIP6601, HIP6602 or HIP6603

and external Intersil MOSFETs provides a precision voltage

regulation system for advanced microprocessors.

Multi-phase power conversion is a marked departure from

earlier single phase converter configurations previously

employed to satisfy the ever increasing current demands of

modern microprocessors. Multi-phase converters, by

distributing the power and load current results in smaller and

lower cost transistors with fewer input and output capacitors.

These reductions accrue from the higher effective

conversion frequency with higher frequency ripple current

due to the phase interleaving process of this topology. For

example, a three phase converter operating at 350kHz will

have a ripple frequency of 1.05MHz. Moreover, greater

converter bandwidth of this design results in faster response

to load transients.

Outstanding features of this controller IC include

programmable VID codes from the microprocessor that

range from 1.05V to 1.825V with a system accuracy of

1%.

Pull up currents on these VID pins eliminates the need for

external pull up resistors. In addition “droop” compensation,

used to reduce the overshoot or undershoot of the CORE

voltage, is easily programmed with a single resistor.

Another feature of this controller IC is the PGOOD monitor

circuit which is held low until the CORE voltage increases,

during its Soft-Start sequence, to within 10% of the

programmed voltage. Over-voltage, 15% above

programmed CORE voltage, results in the converter shutting

down and turning the lower MOSFETs ON to clamp and

protect the microprocessor. Under voltage is also detected

and results in PGOOD low if the CORE voltage falls 10%

below the programmed level. Over-current protection

reduces the regulator RMS output current to 41% of the

programmed over-current trip value. These features provide

monitoring and protection for the microprocessor and power

system.

Features

• Multi-Phase Power Conversion

• Precision Channel Current Sharing

• Precision CORE Voltage Regulation

-

1% System Accuracy Over Temperature

• Microprocessor Voltage Identification Input

- 5-Bit VID Input

- 1.05V to 1.825V in 25mV Steps

- Programmable “Droop” Voltage

• Fast Transient Recovery Time

• Over Current Protection

• Automatic Selection of 2, 3, or 4 Phase Operation

• High Ripple Frequency (Channel Frequency) Times

Number Channels . . . . . . . . . . . . . . . . . .100kHz to 6MHz

• QFN Package:

- Compliant to JEDEC PUB95 MO-220

QFN - Quad Flat No Leads - Package Outline

- Near Chip Scale Package footprint, which improves

PCB efficiency and has a thinner profile

• Pb-free available

Ordering Information

PART NUMBER

PACKAGE

PKG. DWG. #

ISL6552CB

0 to 70

20 Ld SOIC

M20.3

ISL6552CBZ

(See Note)

0 to 70

20 Ld SOIC

(Pb-free)

M20.3

ISL6552CR

0 to 70

20 Ld 5x5 QFN L20.5x5

ISL6552CRZ

(See Note)

0 to 70

20 Ld 5x5 QFN

(Pb-free)

L20.5x5

*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.

NOT RECOMMENDED FOR NEW DE

SIGNS

NO RECOMMENDED REPLACEMEN

T

contact our Technical Support Cente

r at

1-888-INTERSIL or www.intersil.com

/tsc