Datasheet

LT3489
10
3489f
A
VDD
LOAD CURRENT (mA)
0
EFFICIENCY (%)
65
70
75
300
500
3489 TA01b
60
55
50
100 200 400
80
85
90
700600
V
ON
LOAD = 10mA
V
OFF
LOAD = 20mA
TYPICAL APPLICATIO
U
V
IN
V
IN
3.3V
SW
FB
LT3489
L1
2.2µH
D1
R3
5.23k
R2
28.7k
3489 TA04
C2
20µF
C5
0.1µF
C6
0.1µF
C7
0.1µF
C4
2µF
C3
2µF
C1
4.7µF
C
SS
100nF
D7
D2 D3
V
OFF
–8V
20mA
AV
DD
8V
610mA
V
ON
23V
10mA
D6
C8
0.1µF
V
C
GND*
SHDN
3
8
7
14
2
56
SS
COMP
+
D4 D5
C1 TO C8: X5R OR X7R
C1: AVX 08056D475KAT
C2: 2 × 10µF, TAIYO YUDEN LMK316BJ106ML
C3: 2 × 10µF, 10V
C4: 2 × 1µF, AVX08053D105KAT
C5, C6, C7: 0.1µF, 10V
C8: 0.1µF, 16V
D1: DIODES INC. DFLS220L
D2 TO D7: ZETEX BAT54S OR EQUIVALENT
L1: COOPER BUSSMANN SD25-2R2
* EXPOSED PAD MUST ALSO BE GROUNDED
OFF ON
10mA
37.4k
220pF
Transient Response Start-Up Waveforms
A
VDD
100mV/DIV
AC COUPLED
I
L1
1A/DIV
400mA
I
LOAD
200mA
5µs/DIV
3489 TA07
A
VDD
5V/DIV
V
ON
20V/DIV
V
OFF
5V/DIV
I
IN
0.5A/DIV
5ms/DIV
3489 TA08
Effciency