IR3521MTRPBF International Rectifier, IR3521MTRPBF Datasheet - Page 31

• Manufacturer Part Number: IR3521MTRPBF
• Description: IC CTRL XPHASE3 SVID 32-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase3™r

Specifications of IR3521MTRPBF

• Applications: Processor
• Current - Supply: 10mA
• Voltage - Supply: 4.75 V ~ 7.5 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: *
• Package: 32-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 250kHz to 1.5MHz
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

IDD Dynamic OC Limit Capacitor
The latest AMD processors require two over current limits: one for normal thermal design current (TDC) operation and
the other for system IDD_Spike. TDC over-current is set by following instructions outlined in the Over Current Setting
Resistor Rocset section. IDD_Spike occur when the load current exceeds the TDC for a very short duration (10 ms).
Figure 18 shows the boundaries of an event. The current over a moving average of 10 ms does not exceed the TDC
limit. Higher IDD-Spike will last for a shorter duration.
The IDD_Spike over current threshold can be implemented by incorporation a properly sized capacitor between
the OCSET (18) and the IN1 (21) pins (see Figure 19).
OCP-IDDSpike
OCP-TDC
IDDSpike
TDC
Phase IC
Phase IC
Phase IC
Phase IC
Figure 19 C
1
2
3
4
1
IOUT
IOUT
IOUT
IOUT
Figure 18 Showing IDD_Spike Boundaries
2
High-pass filter
R
C
IDDSpike
OCSET
IDDSpike
3
R
C
VDAC
VDAC
and R
4
OCSET1
VDAC
IIN
Page 31
Time (ms)
OCSET
5
comparator
OCSET
6
form a High Pass Filter
Control IC
7
8
9
10
IR3521
V3.03