Data Brief

For further information contact your local STMicroelectronics sales office.

November 2008

Rev 1

1/4

4

STEVAL-ISA050V1

Monolithic VR for chipset and DDR2/3 demonstration board

based on the PM6641

Features

– 0.8 V ±1% voltage reference

– 2.7 V to 5.5 V input voltage range

– Fast response, constant frequency, current

mode control

– Three independent, adjustable, SMPS For

DDR2/3 (VDDQ) and chipset supply

– S3-S5 states compliant DDR2/3 section

– Active soft-end for all outputs

– Selectable tracking discharge for VDDQ

– Separate Power Good signals

– Pulse skipping at light load

– Programmable current limit and soft-start

for all outputs

– Latched OVP, UVP protection

– Thermal protection

and VTT)

– ±2 Apk LDO for DDR2/3 termination (VTT)

with fold back

– Remote VTT output sensing

– High-Z VTT output in S3

– ±15 mA low noise DDR2/3 buffered

reference (VTTREF)

Application

Description

The STEVAL-ISA050V1 demonstration board is

based on the PM6641, that is a monolithic voltage

regulator module, with internal Power MOSFET,

specifically designed to supply DDR2/3 memory

and chipset in ultra-mobile PC and real estate

portable systems. It integrates three independent,

adjustable, constant frequency buck converters, a

±2 Apk low drop-out (LDO) linear regulator and a

±15 mA low noise buffered reference. Each

regulator is provided of basic under voltage (UV)

and over voltage (OV) protections, programmable

soft-start and current limit, active soft-end and

pulse-skipping at light loads.

STEVAL-ISA050V1

www.st.com