LTM4641
APPLICATIONS INFORMATION—MULTIMODE PARALLEL OPERATION
+
–
•ꢀ V
, differentially bussed with V
; use GND
When paralleling n modules, for V
not larger than that given by:
≤1.2V, select R
OUT SET1A
OSNS
OSNS
shielding
–
+
•ꢀ V
, differentially bussed with V
; use GND
V
0.6V
8.2kΩ
OSNS
OSNS
OUT
RSET1A =RSET1B
=
–1 •
(32)
shielding
n
•ꢀ PGOOD,ꢀifꢀused
ForV >1.2V,selectR
notlargerthanthatgivenby:
(33)
OUT
SET1A
Pullinganyonemodule’sRUNpinlowwillpullallmodule’s
HYSTpinslow,toceaseswitchingandoutputvoltageregu-
lation. When paralleling LTM4641 outputs, each module
8.2kΩ
RSET1A =RSET1B
=
n
shouldhaveitsownR
resistorlocally(ifneeded)toset
fSET
Then, determine R
by:
SET2
the on time (I ) consistent with the output voltage set-
ION
2•RSET1A
–n•
ting (cf. Table 1 and Figure 3). Customized UVLO settings,
latchingandnonlatchinginputovervoltagethresholds,and
output overvoltage thresholds need only be configured on
RSET2
=
(34)
VOUT
0.6
RSET1A
8.2kΩ
–1
one LTM4641. INTV and DRV should be connected to
CC
CC
The output voltage setting can be double-checked by:
each other, separatelyoneach module (seeFigures 56 and
66)—or,ifpoweringDRV fromanauxiliarybiasrail,then
CC
RSET1A 2•RSET1A
VOUT = 0.6V 1+n•
+
(35)
by applying the technique of Figure 51 to each module.
8.2kΩ
RSET2
If MSP is used, only one V
need be connected to
INGP
+
The voltage on the V
pins of the modules during
the gate of MSP. The routing of MSP’s source pins to
OSNS
regulation become:
the V of all modules may be difficult to accomplish in
INH
layout without introducing significant loop area; it may be
necessary then to use one MSP MOSFET on the input to
each LTM4641 power stage for practical routing. Also, the
0.6V
∆V
R
GND
(36)
VVOSNS+
=
+
8.2kΩ
+
–
SET1A
||RSET1A ||RSET2
connections of V
and V
to multiple modules
OSNS
OSNS
n
can be difficult to shield, in practice, so leaving provision
for differential-mode filtering of the remote sense signal
16.4kΩ
• RSET1A ||
(C
, C
) local to each modules’ remote-sense input
DM1 DM2
pins is advisable.
n
In multimodule parallel scenarios, V
still given by Equations 12 and 13, respectively.
– and ∆V
are
OSNS
GND
Be aware that the loading of the paralleled remote sense
amplifiers on the bussed feedback signal alters the equa-
tions for setting output voltage as follows.
Lastly, be aware that the total charge current on the
TRACK/SSꢀnetꢀwillꢀbeꢀnꢀ•ꢀ1μA.ꢀ
4641f
37
Linear [ Linear ]
