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
■ Switching section
– 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
■ Reference and termination voltages (VTTREF
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
■ Supply for ultra-mobile PC (UMPC)
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
