Datasheet

LT3420/LT3420-1
17
3420fb
TYPICAL APPLICATIO S
U
3420 TA02
+
V
CC
CHARGE
DONE
SEC
R
REF
LT3420
V
BAT
R
FB
SW
C
T
GND
C2
4.7µF
C3
0.1µF
C1
4.7µF
V
BAT
1.8V TO 5V
V
CC
2.5V TO 10V
CHARGE
DONE
R1
47.5k
T1*
1:12
300V
2
1
3
5
R2
2k
D1
C1: 4.7µF, X5R or X7R, 6.3V
C2: 4.7µF, X5R or X7R, 10V
C4: RUBYCON 220µF PHOTOFLASH CAPACITOR
D1: VISHAY GSD2004S SOT-23
DUAL DIODE. DIODES CONNECTED IN SERIES
T1: KIJIMA MUSEN SBL-6.4
* MAXIMUM AMBIENT TEMPERATURE OF 60°C DICTATED BY TRANSFORMER
DANGER HIGH VOLTAGE
OPERATION BY HIGH VOLTAGE
TRAINED PERSONEL ONLY
C4
220µF
330V
PHOTOFLASH
CAPACITOR
4
9
8
10 5
1
7
632
V
OUT
(V)
50
EFFICIENCY (%)
90
80
70
60
50
40
100
150 200 250
3420 TA03
300 350
V
IN
= 3.3V
V
CC
= V
BAT
= V
IN
V
IN
= 5V
Efficiency
LT3420 Photoflash Charging Circuit Uses Small Transformer