LTC3370EUH Datasheet, PDF (6/10 Pages) Linear Technology – 4-Channel 8A Configurable Buck DC/DCs

DEMO MANUAL DC2311A
Modifying the DC2311A to Other Power Configurations
4. Any switch node associated with a V_IN trace that was
cut will also need to be cut. The SWC/SWD traces and
SWD/SWF traces can be cut in between to pads near the
SW pins as shown in Figure 5. The SWG/SWH traces
only need to be cut for the “4112” configuration. SWH
needs to be cut between the SWH pin and L4 as shown
in Figure 6.
5. For all combinations containing 3A and 4A outputs,
the V_IN nodes of adjoining power stages will need to
be connected together. Connect all V_INs of adjoining
power stages at the V_IN terminals with a 22AWG wire
or larger.
6. All switch nodes of adjoining power stages will need
to be connected together. Each power stage has a pad
to solder a small bus wire, 28AWG. The switch node
pads are also shown in Figure 5 and Figure 6. Care-
fully solder a bus wire as short as possible between
adjoining power stages.
Note: For the 4112 combination switch AB will need to
connect to switch C and switch H. For the 332 combina-
tion switch D will need to connect to switch E.
7. The XAL4020-222M inductors are rated for 5.5A. This
is less than the current limit of the 3A or 4A regulators.
The pads for L1 and L4 as sized to accommodate a
5mm x 5mm inductor such as the Toko FDSD05xx or
the Coilcraft XAL05xx series. Change inductors L1
and/or L4 to accommodate current limit conditions if
needed.
8. Remove any inductors of unused regulators.
Figure 5. Cut SWC and SWD connection near pins
Note: For the 323 configuration, L2 needs to be
populated and L3 needs to be removed to utilize the
regulator 2 FB network.
9. The output capacitance requirement is a minimum
of 22µF for each 1A of output current. Each output
has an optional 0805 capacitor on the bottom of the
board. Add the required amount of capacitance to C5
and/or C29 (shown in Figure 3) for V_OUT1 and V_OUT4
respectively, if needed.
10. Set the EN jumpers of any unused regulators to the
OFF position.
Figure 6. Cut SWH trace between L4 and SWH pin
dc2311af
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