Datasheet

LT3581
31
3581fa
For more information www.linear.com/LT3581
Typical applicaTions
Efficiency
V
BAT
3V TO 36V
(V
BAT
AT START-UP = 6V TO 16V)
100k
10k
24.9k
174k
C1
10µF
2.2nF
3581 TA07a
1µF
C5
47µF
×2
10k
V
OUT
3.3V
0.9A (3V < V
BAT
< 9V)
1.5A (V
BAT
= 9V)
C2
10nF
Q1
C3
4.7µF
C4
2.2µF
SW1 SW2
FB
CLKOUT
GATE
V
C
SS
V
IN
RT
GND
SYNC
FAULT
SHDN
LT3581
47pF
C1: 10µF, 50V, X7R, 1210
C2: 10nF, 25V, X7R, 0603
C3: 4.7µF, 25V, X7R, 1206
C4: 2.2µF, 50V, X7R, 1206
C5: 47µF, 10V, X7R, 1210
D1: CENTRAL SEMI CMHZ5248B-LTZ
D2: CENTRAL SEMI CMMSH2-40
D3: DIODES INC. PD3S230H-7
L1, L2: COILCRAFT MSD7342-332MLB
M1: 2N7002
Q1: MMBT3904
L2
3.3µH
L1
3.3µH
•
•
D2
M1
D3
D1
18V
470pF
10k
200k
Wide Input Range, 3.3V SEPIC Converter Can Operate from 3V to 36V
Wide Input Range SEPIC Can Ride Through V
BAT
Voltages that Are Higher than V
IN_OVP
V
BAT
10V/DIV
V
OUT
2V/DIV
I
L
2A/DIV
3581 TA07c
1s/DIV
V
BAT
= 17V
V
BAT
= 31V
V
OUT
= 3.3V
LOAD CURRENT (mA)
0
50
EFFICIENCY (%)
55
65
70
75
400
80
3581 TA07b
60
1600
800 1200
V
BAT
= 3V
V
BAT
= 9V
V
BAT
= 12V