LTC3412 LINER [Linear Technology], LTC3412 Datasheet - Page 14

• Manufacturer Part Number: LTC3412
• Description: 2.5A, 4MHz, Monolithic Synchronous Step-Down Regulator
• Manufacturer: LINER [Linear Technology]

LTC3412
APPLICATIO S I FOR ATIO
If we set the sum of R2 and R3 to 185k, then the following
equations can be solved:
The last two equations shown result in the following
values for R2 and R3: R2 = 110k , R3 = 75k. The value of
R1 can now be determined by solving the equation shown
below:
A value of 392k will be selected for R1. Figure 4 shows the
complete schematic for this design example.
PC Board Layout Checklist
When laying out the printed circuit board, the following
checklist should be used to ensure proper operation of the
LTC3412. Check the following in your layout.
14
R
1
1
R
+
+
1 393
2
=
+
R
R
185
R
3
R
2
1
3 185
=
k
=
k
=
0 32
0 8
.
.
2 5
0 8
.
.
V
V
k
V
V
U
Top Side
U
W
Figure 3. LTC3412 Layout Diagram
U
1. A ground plane is recommended. If a ground plane layer
is not used, the signal and power grounds should be
segregated with all small-signal components returning to
the SGND pin at one point which is then connected to the
PGND pin close to the LTC3412. The exposed pad should
be connected to SGND.
2. Connect the (+) terminal of the input capacitor(s), C
as close as possible to the PV
provides the AC current into the internal power MOSFETs.
3. Keep the switching node, SW, away from all sensitive
small-signal nodes.
4. Flood all unused areas on all layers with copper. Flood-
ing with copper will reduce the temperature rise of power
components. You can connect the copper areas to any DC
net (PV
in your system).
5. Connect the V
The resistor divider must be connected between V
SGND.
IN
, SV
IN
, V
FB
OUT
pin directly to the feedback resistors.
, PGND, SGND, or any other DC rail
Bottom Side
IN
pin. This capacitor
OUT
3412fb
and
IN
,