ltc3440 Linear Technology Corporation, ltc3440 Datasheet - Page 16

• Manufacturer Part Number: ltc3440
• Description: Micropower Synchronous Buck-boost Dc/dc Converter
• Manufacturer: Linear Technology Corporation

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