IR3084UMTRPBF International Rectifier, IR3084UMTRPBF Datasheet - Page 22

• Manufacturer Part Number: IR3084UMTRPBF
• Description: IC CTLR XPHASE 28-MLPQ
• Manufacturer: International Rectifier
• Series: XPhase™r

Specifications of IR3084UMTRPBF

• Package / Case: 28-MLPQ
• Mounting Type: Surface Mount
• Current - Supply: 14mA
• Voltage - Supply: 9.5 V ~ 16 V
• Operating Temperature: 0°C ~ 100°C
• Applications: Processor
• Package: 28-Lead MLPQ
• Circuit: X-Phase Control IC
• Switch Freq (khz): 150kHz to 1.0MHz
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Fault Modes
Under Voltage Lock Out, VID = FAULT, as well as a low signal on the ENABLE input immediately sets the fault
latch. This causes the EAOUT pin to drive low which turns off the Phase IC drivers. The VRRDY pin also drives
low. The SS/DEL capacitor will discharge down to 0.215V through a 6.5µA current source. If the fault has cleared
when SS/DEL falls to 0.215V then the fault latch will be reset by the discharge comparator allowing a normal
start-up sequence to occur. If a VID = FAULT condition is latched it can only be cleared by cycling power to the
IR3084U on and off.
SS/DEL
(3.85V
DURING
NORMAL
OPERATION)
Over-Current Protection Delay and Hiccup Mode
Figure 11 depicts the operating waveforms of the Over Current Protection (OCP). A delay is included if an over-
current condition occurs after a successful soft start sequence. This delay is required because over-current
conditions can occur as part of normal operation due to load transients or VID transitions. If an over-current fault
occurs during normal operation it will activate the over-current discharge current of 40µA but will not set the fault
latch immediately. If the over-current condition persists long enough for the SS/DEL capacitor to discharge below
the 100mV offset of the delay comparator, the Fault latch will be Se, the error amp’s output will be pulled low,
switching in the phase ICs will be inhibited, and the VRRDY signal will be de-asserted.
The SS/DEL capacitor will continue to discharge until it reaches 0.215V and the fault latch is Reset allowing a
normal soft start to occur. If an over-current condition is again encountered during the soft start cycle the fault
latch will be set without any delay and hiccup mode will begin. During hiccup mode the 11.2 to 1 charge to
discharge current ratio results in a 9% hiccup mode duty cycle regardless of at what point the over-current
condition occurs.
If the SS/DEL pin is pulled below 0.85V, the converter can be disabled.
VOUT
VRRDY
IOUT
NORMAL
OPERATION
Page 22 of 47
OCP
DELAY
Figure 11 – Over-Current Protection Waveforms (VID = 1.1V for simplicity)
3.75V
DISCHARGE VOLTAGE (0.215V)
OCP THRESHOLD
HICCUP OVER-CURRENT
PROTECTION
1.3V
IR3084U
3.77V
RESTART
AFTER
OCP
9/14/2005
NORMAL
OPERATION