| The PM6670 is a complete Double Data Rate (DDR) memory power supply controller designed to meet DDR2/3 JEDEC specifications. It integrates a Constant On-Time (COT) buck controller, a 2Apk sink/source low drop out regulator and a 15mA low noise buffered reference. |
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| The switching controller section is a highperformance (efficiency up to 92%), Constant-On-Time based regulator specifically designed for handling fast load transients over a wide range of input voltages (4.5V to 28V). |
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PM6670 Device Description |
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The COT architecture assures fast transient response supporting both polymeric and ceramic output capacitors. An embedded integrator control loop compensates the DC voltage error due to the output ripple. The DDR2-3 supply voltage VDDQ can be easily set to 1.8V (DDR2) or 1.5V (DDR3) without additional components. The output voltage can also be adjusted in the 0.9V to 2.6V range using an external resistor divider. The 2Apk sink/source linear regulator provides the memory termination voltage with fast load transient response. The output of the linear regulator (VTT) tracks the memory’s reference voltage VTTREF within ±35mV (according to JEDEC spec) over the full operating load conditions. The input of the LDO can be either VDDQ or a lower voltage rail in order to reduce the total power dissipation. The reference voltage (VTTREF) section
provides a voltage equal to one half of VDDQ with an accuracy of 2%.
Main internal blocks of PM6680A
The device is fully compliant with system sleep states
S3 (Suspend-to-RAM) and S4/S5 (Suspend-To-Disk),
providing LDO output high impedance in Suspend-
To-RAM and Tracking Discharge of all outputs in
Suspend-To-Disk.
The S3 and S5 pins are compatible with chipset
interfaces and define the system sleep state.
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 Constant-On-Time topology
No RSENSE current sensing using low side Power MOSFET’s RDS(on)
Soft START internally fixed at 3ms
Selectable minimum frequency (33kHz) in pulse-skip mode
Output voltage ripple compensation
2Apk LDO with foldback for VTT
High-Z VTT output in S3
±15mA low noise buffered reference
Ceramic output capacitor supported
Housed in space-saving VFQFPN 24L
DDR2/3 memory supply
Notebook computers
UMPC
IDTV
HDSTB/STB
PM6670/5 Main Characteristics |
Part Number
|
# of
outputs |
Main
application |
Regulated switching
[VDDQ]
|
Regulated
LDO |
PM6670
|
3 |
DDR2/3
GDDR3/4 |
1.8V, 1.5V, or Adj |
VDDQ / 2
|
PM6675 |
Adj from 0.6V |
Adj from 0.6V |
Part Number
|
LDO
current |
IC supply
voltage |
Output
accuracy |
Package |
PM6670
|
2A pk |
4.5V to 28V |
±1% |
VFQFPN
24 pin 4x4 |
PM6675 |
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PM6670 Product Page