IR3500VMPBF International Rectifier, IR3500VMPBF Datasheet - Page 14

• Manufacturer Part Number: IR3500VMPBF
• Description: The IR3500V Control IC combined with one or more xPhase3 Phase IC implement the control and MOSFET driver functions for a VR11.1 CPU VTT power supply.
• Manufacturer: International Rectifier

Specifications of IR3500VMPBF

• Package: 32-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 250kHz to 1.5MHz
• Pbf: PbF Option Available

Adaptive Voltage Positioning
Adaptive voltage positioning is implemented needed to reduce the output voltage deviations during load transients
and the power dissipation of the load at heavy load. The circuitry related to voltage positioning is shown in Figure 9.
The output voltage is set by the reference voltage VSETPT at the positive input to the error amplifier. This reference
voltage can be programmed to have a constant DC offset bellow the VDAC by connecting RSETPT between VDAC
and VSETPT. The IVSETPT is controlled by the ROSC as shown in Figure 10.
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IVSETPT
Remote
Sense
Amplifier
Figure 10 - ISETPT, OCSET with ROSC
Control IC
VDAC
VDRP
Amplifier
Figure 9 - Adaptive voltage positioning
Error
Amplifier
+
-
-
+
+
-
VSETPT
EAOUT
VDRP
FB
VDAC
IIN
VO
VOSEN+
VOSEN-
RDRP
RSETPT
RFB
ISHARE
VDAC
ISHARE
VDAC
Phase IC
Phase IC
3k
3k
Current Sense
Amplifier
Current Sense
Amplifier
+
-
+
-
CSIN+
CSIN-
CSIN+
CSIN-
July 28, 2008
IR3500V