LTC1872ES6 LINER [Linear Technology], LTC1872ES6 Datasheet - Page 10

• Manufacturer Part Number: LTC1872ES6
• Description: Constant Frequency Current Mode Step-Up DC/DC Controller in SOT-23
• Manufacturer: LINER [Linear Technology]

APPLICATIONS
LTC1872
PC Board Layout Checklist
When laying out the printed circuit board, the following
checklist should be used to ensure proper operation of the
LTC1872. These items are illustrated graphically in the
layout diagram in Figure 5. Check the following in your
layout:
1. The Schottky diode should be closely connected
2. The (+) plate of C
3. The input decoupling capacitor (0.1 F) should be
10
between the output capacitor and the drain of the
external MOSFET.
resistor as closely as possible. This capacitor provides
AC current to the inductor.
connected closely between V
(Pin 2).
U
C
IN
R
ITH
ITH
INFORMATION
U
should connect to the sense
BOLD LINES INDICATE HIGH CURRENT PATHS
Figure 5. LTC1872 Layout Diagram (See PC Board Layout Checklist)
IN
W
R1
(Pin 5) and ground
1
2
3
I
GND
V
TH
FB
/RUN
LTC1872
R2
SENSE
U
NGATE
V
IN
–
6
5
4
0.1 F
4. Connect the end of R
5. The trace from SENSE
6. Keep the switching node NGATE away from sensitive
7. The V
+
possible. The V
comparator.
should be kept short. The trace should connect close
to R
small signal nodes.
resistors. The resistive divider R1 and R2 must be
connected between the (+) plate of C
ground.
C
R
IN
S
SENSE
FB
pin should connect directly to the feedback
.
L1
+
IN
pin is the SENSE
D1
C
OUT
SENSE
–
M1
(Pin 4) to the Sense resistor
as close to V
1872 F05
V
V
IN
OUT
+
OUT
of the current
IN
and signal
(Pin 5) as