PM6641 STMicroelectronics, PM6641 Datasheet - Page 41

• Manufacturer Part Number: PM6641
• Description: IC MONO VR DDR2/3 PC VFQFPN-48
• Manufacturer: STMicroelectronics

Specifications of PM6641

• Applications: Converter, DDR2, DDR3
• Voltage - Input: 2.7 ~ 5.5 V
• Number Of Outputs: 3
• Voltage - Output: 0.8 ~ 5.5 V
• Operating Temperature: 0°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-VFQFN
• Output Voltage: 0.9 V
• Output Current: 3 A
• Input Voltage: 2.7 V to 5.5 V
• Switching Frequency: 1000 KHz
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• For Use With: 497-8425 - KIT EVAL PM6641 CHIPSET/DDR2/3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PM6641
9
9.1
Application examples
The following application examples are typical or customized applications. Each example
has been tested and evaluated and the schematic and BOM are available for reference
design.
UMPC DDR2 and chipset power supply
Figure 34. System architecture for DDR2 and chipset power supply
This application is conceived for real estate constrained portable equipment with DDR2
memory. An input power voltage pre-regulated to 3.3 V or 5 V is available and the available
output maximum power levels are shown in
is estimated to be about 50% of the maximum load; this upper limit must be respected in
order to avoid dangerous stresses for internal power MOSFETs. The following table
resumes these current values.
Table 12.
1.8 V (VDDQ)
0.9 V (VTT)
Output rail
3.3V
1.05 V
1.5 V
Expected average and peak currents for DDR2 and chipset power supply
PM6641
Doc ID 13510 Rev 3
Max non continuous load [A]
2.8
Figure 34
2.5
±2
4
. The switching regulator average load
Expected average load [A]
Application examples
1.5V @
1.05V @ 4A
VTT (LDO)
0.9V @ 2A
1.8V @
VDDQ
1.3
0.3
1.4
2
2.8A
2.5A
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