Datasheet
MCP1650/51/52/53
DS21876B-page 20 2004-2013 Microchip Technology Inc.
6.0 TYPICAL LAYOUT
FIGURE 6-1: MCP1650/51/52/53 Application Schematic.
When designing the physical layout for the MCP1650/
51/52/53, the highest priority should be placing the
boost power train components in order to minimize the
size of the high current paths. It is also important to pro-
vide ground-path separation between the large-signal
power train ground and the small signal feedback path
and feature grounds. In some cases, additional filtering
on the V
IN
pin is helpful to minimize MCP1650/51/52/53
input noise.
In this layout example, the critical power train paths are
from input to output, +V
IN
_
1 to F
1
to C
2
to L
1
to Q
1
to
GND. Current will flow in this path when the switch (Q
1
)
is turned on. When Q
1
is turned off, the path for current
flow will quickly change to +V
IN
_
1 to F
1
to L
1
to D
1
to
C
1
to R4 to GND. When starting the layout for this appli-
cation, both of these power train paths should be as
short as possible. The C
2
, Q
1
and R
4
GND connections
should all be connected to a single “Power Ground”
plane to minimize any wiring inductance.
Bold traces are used to represent high-current
connections and should be made as wide as is
practical.
R
1
and C
3
is an optional filter that reduces the
switching noise on the V
IN
pin of the MCP1650/51/52/
53. This should be considered for high-power
applications (> 1W) and bootstrap applications where
V
IN
of the MCP1650/51/52/53 is supplied by the output
voltage of the boost regulator.
The feedback resistor divider that sets the output
voltage should be considered sensitive and be routed
away from the power-switching components discussed
previously.
As shown in the diagram, R
6
, R
8
and the GND pin of
the MCP1650/51/52/53 should be returned to an
analog ground plane.
The analog ground plane and power ground plane
should be connected at a single point close to the input
capacitor (C
2
).
Single-Cell Li-Ion
Input (2.8V to 4.8V)
+5V Output @ 1A
Low Input
Coilcraft
®
DO1813HC
PGND
PGND
PGND
AGND
AGND
C3
0.1μ
C2
47μ
TP1
+V
IN
_1
TP2
+V
OUT
_1
TP4
GND
R5
73.2K
R8
49.9K
AGND
AGND
VR
VR
00
0
0
0
0
0
D1
3.3 μH
B330ADIC
L1
R3
3.09K
R7
562
R6
1K
MCP1651_MSOP
3
1
4
2
5
6
7
8
D2
LED
F1
MCP1651R
(+2.8V to +4.8V Input to +5V Output @ 1A)
2A Power Train Path
Q1
IRLML2502
/SHDN
LBI
GND
CS
EXT
FB
/LBO
V
IN
R2
49.9K
Keep Away From Switching Section
TP5
/SHDN1
R4
0.1
TP3
GND
C1
47μ
FUSE
R1
100