IR3086AMPBF International Rectifier, IR3086AMPBF Datasheet - Page 11

• Manufacturer Part Number: IR3086AMPBF
• Description: IC PHASE CONTROLLER OVP 20MLPQ
• Manufacturer: International Rectifier
• Series: XPhase™r

Specifications of IR3086AMPBF

• Applications: Processor
• Current - Supply: 10mA
• Voltage - Supply: 8.4 V ~ 14 V
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 20-MLPQ
• Ic Function: Phase IC With Fault And OverTemp Detect
• Supply Voltage Range: 8.4V To 14V, 6V To 25V, 6V To 14V
• Operating Temperature Range: -40°C To +150°C
• Digital Ic Case Style: MLPQ
• No. Of Pins: 20
• Rohs Compliant: Yes
• Package: 20-Lead MLPQ
• Circuit: X-Phase Phase IC
• Iout (a): 2.5A Gate Driver
• Pbf: PbF Option Available
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *IR3086AMPBF

IR3086A THEORY OF OPERATION
Block Diagram
The Block diagram of the IR3086A is shown in Fig. 6, and specific features are discussed in the following sections.
Tri-State Gate Drivers
The gate drivers can deliver up to 3A peak current. An adaptive non-overlap circuit monitors the voltage on the
GATEH and GATEL pins to prevent MOSFET shoot-through current while minimizing body diode conduction.
An Enable signal is provided by the Control IC to the Phase IC without the addition of a dedicated signal line. The
Error Amplifier output of the Control IC drives low in response to any fault condition such as input under voltage or
output overload. The IR3086A Body Braking
state operation prevents negative inductor current and negative output voltage during power-down.
The Gate Drivers revert to a high impedance “off” state if VCCL and VCCH supply voltages are below the normal
operating range. An 80k
GATEH/GATEL voltage from rising due to leakage or other causes under these conditions.
Over Voltage Protection (OVP)
The IR3086A includes over-voltage protection that turns on the low side MOSFET to protect the load in the event of
a shorted high-side MOSFET or connection of the converter output to an excessive output voltage. A comparator
monitors the voltage at the CSIN- pin which is usually connected directly to the converter output. If the voltage
exceeds the DACIN voltage plus 125mV typical (100mV minimum and 160mV maximum) the GATEL pin drives
high. The OVP circuit overrides the normal PWM operation and will fully turn-on the low side MOSFET within
approximately 150ns. The low side MOSFET will remain ON until the over-voltage condition ceases.
PWMRMP
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RMPIN+
RMPIN-
SCOMP
ISHARE
HOTSET
BIASIN
VRHOT
EAIN
LGND
RAMP
SLOPE
ADJUST
RAMP
COMPARATOR
BIASIN
10K
+
-
SYSTEM
REFERENCE
VOLTAGE
VDAC
VRHOT
COMPARATOR
+
-
SCOMP
resistor is connected across the GATEH/GATEL and PGND pins to prevent the
CLOCK
PULSE
GENERATOR
+
-
SHARE
ADJUST
ERROR
AMP
+
-
20mV
VOLTAGE
PROPORTIONAL
TO ABSOLUTE
TEMPERATURE
RAMP
DISCHARGE
CLAMP
ENABLE
Figure 6 – IR3086A Block Diagram
ENABLE
PWM
COMPARATOR
+
-
-
+
TM
+
VDAC
VDAC
comparator detects this and drives both gate outputs low. This tri-
+
X
0.91
BODY BRAKING
COMPARATOR
PWM
LATCH
DOMINANT
S
RESET
R
+
-
CURRENT
SENSE
AMP
X34
+
-
OVP
COMPARATOR
GATE
NON-OVERLAP
COMPARATORS
-
+
-
+
125mV
+
-
+
-
+
-
IR3086APbF
FAULT
COMPARATOR
2V
INTERNAL
CIRCUIT
BIAS
May 13, 2009
VCC
VCCH
GATEH
VCCL
GATEL
PGND
VCC
DACIN
CSIN+
CSIN-
PHSFLT