IR3523MTRPBF International Rectifier, IR3523MTRPBF Datasheet - Page 21

• Manufacturer Part Number: IR3523MTRPBF
• Description: IC XPHASE3 CTLR VR11.1 40-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase3™r

Specifications of IR3523MTRPBF

• 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: 40-MLPQ
• Ic Function: Dual Output Control IC
• Supply Voltage Range: 4.75V To 7.5V
• Operating Temperature Range: 0°C To +150°C
• Digital Ic Case Style: MLPQ
• No. Of Pins: 40
• Controller Type: XPhase
• Rohs Compliant: Yes
• Package: 40-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

Enable Input
Pulling the ENABLE pin below 1.0 V sets the Fault Latch. Forcing ENABLE to a voltage above 1.65V results in the
3-bit VID codes to be read and stored. SS/DEL
fault conditions are present.
Over Voltage Protection (OVP)
Output over-voltage might occur due to a high side MOSFET short or if the output voltage sense path is
compromised. If the over-voltage protection comparators sense that either VOUT
125mV, the over voltage fault latch is set which pulls the error amplifier output low turning off both converters power
stage. The IR3523 communicates an OVP condition to the system by raising the ROSC pin voltage to within
V(VCCL) – 1.2 V. An OVP condition is also communicated to the phase ICs by forcing the IIN pin (which is tied to
the ISHARE bus and ISHARE pins of the phase ICs) to VCCL as shown in Figure 14. In each phase IC, the OVP
circuit overrides the normal PWM operation to ensure the low side MOSFET turn-on within approximately 130ns.
The low side MOSFET will remain on until the ISHARE pins fall below V(VCCL) - 800mV. An over voltage fault
condition is latched in the IR3523 and can only be cleared by cycling the power to VCCL.
During dynamic VID down at light to no load, false OVP triggering is prevented by increasing the OVP threshold to a
fixed 1.2 V (VOUT1) and 1.8 V (VOUT2) whenever a dynamic VID is detected and the difference between output
voltage and the fast internal VDAC is more than 50mV, as shown in Figure 15. The over-voltage threshold is
changed back to VDAC+125mV if the difference between output voltage and the fast internal VDAC is less than
50mV.
The overall system must be considered when designing for OVP. In many cases the over-current protection of the
AC-DC or DC-DC converter supplying the multiphase converter will be triggered thus providing effective protection
without damage as long as all PCB traces and components are sized to handle the worst-case maximum current. If
this is not possible, a fuse can be added in the input supply to the multiphase converter.
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(PHASE IC)
(PHASE IC)
OUTPUT
VOLTAGE
IIN
(PHASE IC
ISHARE)
FAULT
LATCH
ERROR
AMPLIFIER
OUTPUT
(EAOUT)
GATEH
GATEL
(Vout)
VCCL-800 mV
VDAC
OVP
THRESHOLD
Figure 14 - Over-voltage protection during normal operation
NORMAL OPERATION
X
pins are also allowed to begin their power-up cycles as long as no
OVP CONDITION
X
pin voltage exceeds VDAC
June 20, 2008
AFTER
OVP
IR3523
X
by