LTC3440_15 Datasheet, PDF (16/20 Pages) Linear Technology – Micropower Synchronous Buck-Boost DC/DC Converter

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