Datasheet

LT3579/LT3579-1
33
35791fa
For more information www.linear.com/LT3579
TYPICAL APPLICATION
L
2
3.3µH
0.22µF
L1
3.3µH
D3
D2
D4
V
OUT
3.3V
1.8A (V
BAT
= 3V)
3.1A (V
BAT
= 9V)
3.4A (V
BAT
≥
12V)
V
BAT
3V TO 33V (OPERATING)
6V TO 16V (START-UP)
35791 TA07a
24.9k
8.25k
10k
174k
100k
200k
10k
•
•
C
OUT
47µF
×6
C
VIN
10µF
C1
10nF
D1
15V
M1
C
PWR
4.7µF
×2
C2
4.7µF
C1: 10nF, 16V, X7R, 0603
C
VIN
: 10µF, 16V, X7R, 1206
C
PWR
, C2: 4.7µF, 50V, X7R, 1210
C
OUT
: 47µF, 6.3V, X7R, 1210
D1: CENTRAL SEMI CMHZ5245B-LTZ
D2: VISHAY SS5P6
D3: CENTRAL SEMI CMMSH2-40
D4: CENTRAL SEMI CMMSH2-40
L1, L2: WÜRTH WE-DD 744870003
M1: 2N7002
Q1: MMBT3904
4.7nF
100pF
V
IN
SW1 SW2
LT3579
SHDN
FAULT
CLKOUT
GATE
FB
VC
SYNC GND SS
RT
Q1
4.7nF
500kHz SEPIC Converter Generates 3.3V from a 3V to 33V Input
LOAD CURRENT (A)
0
10
EFFICIENCY (%)
POWER LOSS (W)
50
60
70
80
40
30
20
90
0
2
2.5
3
3.5
1.5
1
0.5
4
1.5 2 2.5 3 3.5 40.5 1
35791 TA08a
V
BAT
= 12V
V
BAT
= 3V
Efficiency and Power Loss
50ms/DIV
V
OUT
2V/DIV
V
BAT
10V/DIV
I
L1 +
I
L2
1A/DIV
35791
TA08b
Transient Response with 9V to 33V to 9V V
BAT
Glitch (R
LOAD
= 1.5Ω)