Datasheet

LTM4616
14
4616ff
For more information www.linear.com/LTM4616
applications inForMation
Figure 2. 6-Phase Operation
Figure 3. 12-Phase Operation
4616 F02
0
+120
PHASE 1
CLKOUTCLKIN
PHMODE
120
PHASE 3
CLKOUTCLKIN
PHMODE
240
+180+120
PHASE 5
CLKOUTCLKIN
PHMODES
VIN
(420)
60
PHASE 2
CLKOUTCLKIN
PHMODE
+120
180
PHASE 4
CLKOUTCLKIN
PHMODE
+120
300
PHASE 6
CLKOUTCLKIN
PHMODE
4616 F03
0
+120
PHASE 1
CLKOUTCLKIN
PHMODE
120
PHASE 5
CLKOUTCLKIN
PHMODE
240
+180+120
PHASE 9
CLKOUTCLKIN
PHMODES
VIN
(420)
60
PHASE 3
CLKOUTCLKIN
PHMODE
+120
180
PHASE 7
CLKOUTCLKIN
PHMODE
+120
300
PHASE 11
CLKOUTCLKIN
PHMODE
OUT2
OUT1V
IN
90
+120
PHASE 4
CLKOUTCLKIN
PHMODE
210
PHASE 8
CLKOUTCLKIN
PHMODE
330
+180+120
PHASE 12
CLKOUTCLKIN
PHMODES
VIN
(510)
150
(390)
30
PHASE 6
CLKOUTCLKIN
PHMODE
+120
270
PHASE 10
CLKOUTCLKIN
PHMODE
+120
PHASE 2
CLKOUTCLKIN
PHMODE
LTC6908-2
The LTM4616 device is an inherently current mode con-
trolled device,
so parallel modules will have very good cur-
rent sharing. This will balance the thermals on the design.
Ti
e the I
TH
pins of each LTM4616 together to share the
current. Current sharing is inherently guaranteed by the
current mode operation of the LTM4616’s DC/DC regula
-
tors. Moreover, the accuracy of current sharing between
the two outputs is approximately ±15%. To reduce ground
potential noise, tie the I
THM
pins of all LTM4616s together
and then connect to the SGND of the master at the point it
connects to the output capacitor GND. See layout guideline
in Figure 17. Figure 19 shows a schematic of the parallel
design. The FB pins of the parallel module are tied together.
Input RMS Ripple Current Cancellation
Application Note 77 provides a detailed explanation of
multiphase operation. The input RMS ripple current can
-
cellation mathematical
derivations are presented, and a
graph is displayed representing the RMS ripple current
reduction as a function of the number of interleaved phases.
Figure 4 shows this graph.