ISL6244 Datasheet, PDF (9/25 Pages) Intersil Corporation – Multi-Phase PWM Controller

ISL6244
Theory of Operation
Multi-Phase Power Conversion
Microprocessor load current profiles have changed to the
point where the multi-phase power conversion advantage is
pronounced. The technical challenges associated with
producing a single-phase converter which is both cost-
effective and thermally viable have forced a change to the
cost-saving approach of multi-phase. The ISL6244 controller
helps reduce the complexity of implementation by integrating
vital functions and requiring minimal output components.
The block diagram in Figure 12 provides a top level view of
multi-phase power conversion using the ISL6244 controller.
VID4
VID3
VID2
VID1
VID0
FB
COMP
OFS
VDIFF
VSEN
RGND
IOUT
PGOOD
VCC
EN
FS
1.23V
DYNAMIC
VID
DAC
UV
e/a
x 0.2
100µA
6V
POR
AND
SOFT START
OSCILLATOR
AND
SAWTOOTH
+
+
-
+
+-
+
+-
+
+-
OV
2.2V
OC
diff
AVERAGE
1/N
+
+
+
+
I1
I2
CURRENT
SENSE
&
I3 ^PHASE
DETECT
I4
VFF
PWM1
PWM2
PWM3
PWM4
ISEN1
ISEN2
ISEN3
ISEN4
N PHASES
85µA
GND
FIGURE 12. BLOCK DIAGRAM
9
FN9106.3
December 28, 2004