Datasheet

16
LTC3440
3440fb
TYPICAL APPLICATIO S
U
Low Profile (<1.1mm) Li-Ion to 3.3V at 200mA Converter
SW1
V
IN
SHDN/SS
MODE/SYNC
R
T
SW2
V
OUT
FB
V
C
GND
3
7
8
2
1
4
6
9
10
5
LTC3440
L1
4.7μH
R1
340k
R2
200k
R3
15k
3440 TA04a
R
T
30.1k
C1: TAIYO YUDEN JMK212BJ475MG
C2: TAIYO YUDEN JMK212BJ475MG
L1: COILCRAFT LPO1704-472M
*1 = Burst Mode OPERATION
0 = FIXED FREQUENCY
f
OSC
= 2MHz
C1
4.7μF
Li-Ion
V
IN
= 2.5V TO 4.2V
*
+
C4
1.5nF
C2
4.7μF
V
OUT
3.3V
200mA
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3440 TA04b
0
1
Burst Mode
OPERATION
V
IN
= 2.5V
V
IN
= 3.3V
V
IN
= 4.2V
Efficiency
3-Cell to 5V Boost Converter with Output Disconnect
SW1
V
IN
SHDN/SS
MODE/SYNC
R
T
SW2
V
OUT
FB
V
C
GND
3
7
8
2
1
4
6
9
10
5
LTC3440
L1
10μH
R1
619k
R2
200k
3440 TA06a
R
T
60.4k
C1: TAIYO YUDEN JMK212BJ106MG
C2: TAIYO YUDEN JMK325BJ226MM
D1: ON SEMICONDUCTOR MBRM120T3
L1: SUMIDA CDRH4D28-100
*1 = Burst Mode OPERATION
0 = FIXED FREQUENCY
** LOCATE COMPONENTS AS
CLOSE TO IC AS POSSIBLE
C1
10μF
C3
0.1μF
3
CELLS
R4 1M
V
IN
= 2.7V TO 4.5V
*
SD
C4
1.5nF
15k
f
OSC
= 1MHz
C2**
22μF
V
OUT
5V
300mA
+
D1**
OUTPUT CURRENT (mA)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.1 10 100 1000
3440 TA06b
0
1
Burst Mode
OPERATION
V
IN
= 2.7V
f
OSC
= 1MHz
V
IN
= 3.6V
V
IN
= 4.5V
3-Cell to 5V Boost Efficiency