Datasheet

C
IN_BYP
R
FBT
C
SS
R
FBB
C
OUT_BYP
SH SS FB
SYNC
EN
PGND
V
OUT
AGND
Enable
VIN
VOUT
Share
Clk
MASTER
LOAD
C
IN_BYP
C
OUT_BYP
SH SS FB
SYNC
EN
PGND
AGND
Enable
VIN
VOUT
Share
Clk
SLAVE
V
IN
C
IN_BULK
C
OUT_BULK
X
X
LMZ22010
www.ti.com SNVS687G –MARCH 2011–REVISED OCTOBER 2013
In a current sharing system using two or more modules, the slaves have their error amp circuitry disconnected.
The master over-rides the error amplifier outputs of the slaves. This signal is then compared to each module’s
individual current sense circuitry. Due to this, the current sense gain of the entire system increases according to
the number of modules slaved to the master. To compensate for this and ensure good stability, the total output
capacitance has to be increased. For example, two modules configured to provide 1.2V
OUT
and 20 amps have a
required total bulk output capacitance of C
OUT_BULK
= 2 x 450µF (ESR 25mOhms). This is a thirty six percent
increase in the required output capacitance of a stand alone module. Up to 6 modules can be connected in
parallel for loads up to 60A. For more information on current sharing refer to AN-2093 (Current sharing
evaluation board).
Figure 53. Current Sharing Example Schematic
Figure 54. Output voltage ripple of two modules with synchronization clocks in phase
Figure 55. Output voltage ripple of two modules with synchronization clocks 180 degrees out of phase
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