Manual

MAX1802
Digital Camera Step-Down
Power Supply
______________________________________________________________________________________ 15
OSC
45
VL
VL
REFREF
OSC
GND
DCON1 DCON2 DCON3 DL3
20
DL1
D1
D2
D3 D4
Q3
Q4 Q5
D
6
Q2
DL2
FB1
12 15
FB2
19 16
DHM
LXM
DLM
PGNDM
FBM
VDDC
LXC FBC
FB3 VL
28 22 23 18 11 31 10 24 13
3 2
29 14 17 21
ONC ON1 ONM COMPM COMPC COMP1 COMP2 COMP3
VH
VDDM
PGND
2532
0.1µF
1µF
0.1µH
1µF
10µH
10µH
100µF
10µF
1µF
1µF
1µF
1µF
4.7µH
4.7µF
464k 100k
100pF
40.2k
10µF
DCON
D5
Q1
GND
IN
COMP
DL
MAX1802
OFF
ON
6 7 8 9 1 27 26 30
CORE
MAIN
+12V
+3.3V
+1.8V
LCD BIAS +18V -7.5V CCD BIAS +15V
100k
100k
100k
100k
165k
44.2k
1.34MΩ
MAX1801
C
C3
1000pF
C
C2
1000pF
C
C1
1000pF
C
CC
470pF
C
CM
4.7nF R
CM
33k
R
CC
90k
R
C1
10k
R
C2
10k
R
C3
10k
2
4 3 1
7
5 6 8
C
OSC
R
OSC
INPUT
2.5V TO 11V
+5V
MOTOR DRIVE
+7V
BACKLIGHT
Q
1
, Q
2
, Q
3
: FDN337N
Q
4
, Q
5
: SEE MOSFET SELECTION SECTION
D
1
, D
2
, D
3
, D
4
: CMSD-4448
D
5
: MBR0502L
1.1MΩ
0.1µF
Figure 1. Typical Application Circuit