LTC3415 Datasheet, PDF (10/28 Pages) Linear Technology – 7A, PolyPhase Synchronous Step-Down Regulator

LTC3415
OPERATION
other by programming the PHMODE pin of each LTC3415
to different levels. For example, a slave stage that is 180
degrees out of phase from the master can generate a
CLKOUT signal that is 300 degrees (PHMODE = 0) away
from the master for the next stage, which then can gener-
ate a CLKOUT signal that’s 420, or 60 degrees (PHMODE
= SV_IN/2) away from the master for its following stage.
Refer to Figure 2 for configurations of 2-phase, 3-phase,
4-phase, 6-phase and 12-phase operation.
A multiphase power supply significantly reduces the amount
of ripple current in both the input and output capacitors.
The RMS input ripple current is divided by, and the effective
ripple frequency is multiplied by, the number of phases used
(assuming that the input voltage is greater than the number
0
+120
CLKIN CLKOUT
PHMODE
PHASE 1
120
+120
CLKIN CLKOUT
PHMODE
S_VIN
PHASE 3
240
+180
CLKIN CLKOUT
(420)
60
+120
CLKIN CLKOUT
PHMODE
PHASE 5
PHMODE
PHASE 2
Figure 2d. 6-Phase Operation
180
+120
CLKIN CLKOUT
PHMODE
SV_IN
2
PHASE 4
300
CLKIN CLKOUT
PHMODE
PHASE 6
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0
+90
CLKIN CLKOUT
90
+90
CLKIN CLKOUT
180
+90
CLKIN CLKOUT
SV_IN
PHMODE
2
PHASE 1
SV_IN
PHMODE
2
PHASE 4
SV_IN
PHMODE
2
PHASE 7
270
+120
CLKIN CLKOUT
PHMODE
SV_IN
2
PHASE 10
(390)
30
+90
CLKIN CLKOUT
PHMODE
PHASE 2
120
+90
CLKIN CLKOUT
210
+90
CLKIN CLKOUT
SV_{IN PHMODE}
2
PHASE 5
SV_{IN PHMODE}
2
PHASE 8
300
+120
CLKIN CLKOUT
PHMODE
SV_IN
2
PHASE 11
(420)
60
+90
CLKIN CLKOUT
PHMODE
SV_IN
2
PHASE 3
150
+90
CLKIN CLKOUT
PHMODE
PHASE 6
240
+90
CLKIN CLKOUT
330
CLKIN CLKOUT
SV_IN
PHMODE
2
PHASE 9
SV_{IN PHMODE}
2
PHASE 12
Figure 2e. 12-Phase Operation
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