PM6670AS Datasheet, PDF (1/54 Pages) STMicroelectronics – Complete DDR2/3 memory power supplies controller

PM6670AS
Complete DDR2/3 memory power supplies controller
Features
■ Switching section (VDDQ)
– 4.5 V to 36 V input voltage range
– 0.9 V, ±1 % voltage reference
– 1.8 V (DDR2) or 1.5 V (DDR3) fixed output
voltages
– 0.9 V to 2.6 V adjustable output voltage
– 1.237 V ±1 % reference voltage available
– Very fast load transient response using
constant-on-time control loop
– No R_SENSE current sensing using low side
MOSFETs' R_DS(ON)
– Negative current limit
– Latched OVP and UVP
– Soft-start internally fixed at 3 ms
– Selectable pulse skipping at light load
– selectable No-Audible (33 kHz) pulse skip
mode
– Ceramic output capacitors supported
– Output voltage ripple compensation
■ VTT LDO and VTTREF
– 2 Apk LDO with foldback for VTT
– Remote VTT sensing
– High-Z VTT output in S3
– Ceramic output capacitors supported
– ±15 mA Low noise buffered reference
Applications
■ DDR2/3 memory supply
■ Digital TV system
■ SSTL18, SSTL15 and HSTL bus termination
VFQFPN-24 4x4
Description
The device PM6670AS is a complete DDR2/3
power supply regulator designed to meet JEDEC
specifications.
It integrates a Constant On-Time (COT) buck
controller, a 2 Apk sink/source Low Drop Out
regulator and a 15 mA low noise buffered
reference.
The COT architecture assures fast transient
response supporting both electrolytic and ceramic
output capacitors. An embedded integrator
control loop compensates the DC voltage error
due to the output ripple.
The 2 Apk sink/source linear regulator provides
the memory termination voltage with fast load
transient response.
The device is full compliant with system sleep
states S3 and S4/S5, providing LDO output high
impedance in Suspend-To-RAM and Tracking
Discharge of all outputs in Suspend-To-Disk.
Table 1. Device summary
Part number
PM6670AS
PM6670ASTR
February 2008
Package
VFQFPN-24 4x4 (Exposed pad)
Rev 1
Packaging
Tube
Tape and reel
1/54
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