Datasheet

14
LT3466-1
34661f
1
2
3
4
5
10
9
8
7
6
C
OUT1
R
FB1
R
T
CTRL1
CTRL2
34661 F10
R2
R1
C
OUT2
C
IN
V
IN
GND
GND
L1
L2
11
Figure 11. Recommended Component Placement
APPLICATIO S I FOR ATIO
WUUU
The V
CE(SAT)
and V
BE(SAT)
values for the transistor Q1 can
be obtained from the Philips BC807 data sheet:
R
VV
mA
BASE
=
+1650109
075
–..
.
R
BASE
= 13.6k
Picking the closest 1% resistor value yields:
R
BASE
= 14k
BOARD LAYOUT CONSIDERATION
As with all switching regulators, careful attention must be
paid to the PCB board layout and component placement.
To prevent electromagnetic interference (EMI) problems,
proper layout of high frequency switching paths is essen-
tial. Minimize the length and area of all traces connected to
the switching node pins (SW1 and SW2). Keep the feed-
back pins (FB1 and FB2) away from the switching nodes.
The DFN package has an exposed paddle that must be
connected to the system ground. The ground connection
for the feedback resistors should be tied directly to the
ground plane and not shared with any other component,
except the R
T
resistor, ensuring a clean, noise-free con-
nection. Recommended component placement is shown
in the Figure 11.