IR3081 International Rectifier Corp., IR3081 Datasheet - Page 6

• Manufacturer Part Number: IR3081
• Description: Xphasetm Vr 10 Control Ic
• Manufacturer: International Rectifier Corp.

SYSTEM THEORY OF OPERATION
XPhase
The XPhase
requiring small size, design flexibility, low voltage, high current and fast transient response. The architecture can
control converters of any phase number where flexibility facilitates the design trade-off of multiphase converters.
The scalable architecture can be applied to other applications which require high current or multiple output voltages.
As shown in Figure 1, the XPhase
each using a single Phase IC. The Control IC communicates with the Phase ICs through a 5-wire analog bus, i.e.
bias voltage, phase timing, average current, error amplifier output, and VID voltage. The Control IC incorporates all
the system functions, i.e. VID, PWM ramp oscillator, error amplifier, bias voltage, and fault protections etc. The
Phase IC implements the functions required by the converter of each phase, i.e. the gate drivers, PWM comparator
and latch, over-voltage protection, and current sensing and sharing.
There is no unused or redundant silicon with the XPhase
controller that can be configured for 2, 3, or 4 phase operation. PCB Layout is easier since the 5 wire bus
eliminates the need for point-to-point wiring between the Control IC and each Phase. The critical gate drive and
current sense connections are short and local to the Phase ICs. This improves the PCB layout by lowering the
parasitic inductance of the gate drive circuits and reducing the noise of the current sense signal.
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ENABLE
12V
VID5
VID0
VID1
VID2
VID3
VID4
TM
Architecture
TM
architecture is designed for multiphase interleaved buck converters which are used in applications
IRU3081
CONTROL
IC
>> BIAS VOLTAGE
>> PHASE TIMING
<< CURRENT SENSE
>> PWM CONTROL
>> VID VOLTAGE
CONTROL BUS
TM
architecture consists of a Control IC and a scalable array of phase converters
Figure 1. System Block Diagram
PHASE FAULT
CURRENT SHARE
PHASE HOT
PHASE FAULT
CURRENT SHARE
PHASE HOT
ADDITIONAL PHASES
IRU3086
PHASE
IC
IRU3086
PHASE
IC
TM
architecture compared to others such as a 4 phase
CCS
CCS
0.1uF
0.1uF
RCS
RCS
INPUT/OUTPUT
CIN
COUT
10/01
IR3081
/04
POWER GOOD
PHASE FAULT
VR HOT
VOUT SENSE+
VOUT+
VOUT-
VOUT SENSE-