PM6641 Datasheet, PDF (1/47 Pages) STMicroelectronics – Monolithic VR for chipset and DDR2/3 supply for ultra-mobile PC (UMPC) applications

PM6641
Monolithic VR for chipset and DDR2/3 supply
for ultra-mobile PC (UMPC) applications
Features
■ 0.8 V ±1 % internal voltage reference
■ 2.7 V to 5.5 V input voltage range
■ Fast response, constant frequency,
current mode control
■ Three independent, adjustable, out-of-phase
SMPS for DDR2/3 (VDDQ) and chipset supply
■ Low noise DDR2/3 reference (VTTREF)
■ ±2 Apk LDO for DDR2/3 termination (VTT)
with foldback
■ S0-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
Applications
■ DDR2/3 memory and chipset supply
■ UMPC and portable equipment
■ Handheld and PDAs
VFQFPN-48 7x7
Description
The PM6641 is a monolithic voltage regulator
module specifically designed to supply DDR2/3
memory and chipset in ultra-mobile PC and real
estate constrained 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 provides basic UV and OV
Protections, programmable Soft-Start and Current
Limit and active Soft-End.
Pulse-Skipping technique is performed to
increase efficiency at very light load.
Table 1. Device summary
Part number
PM6641
PM6641TR
January 2008
Package
VFQFPN-48 7x7 (exposed pad)
VFQFPN-48 7x7 (exposed pad
Rev 2
Packaging
Tray
Tape & reel
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