Datasheet

LT3973/LT3973-3.3/LT3973-5
20
3973fa
Typical applicaTions
Input Current During Start-Up Start-Up from High Impedance Input Source
5V Step-Down Converter with Undervoltage Lockout
V
IN
BOOST
LT3973
SWEN/UVLO
PG
RT
0.47µF
15pF
22µF
4.7µF
V
IN
6V TO 42V
V
OUT
5V
750mA
1M
316k
215k
3.9M
kΩ
f = 600kHz
15µH
BD
OUT
FB
GND
3973 TA10a
976k
+
–
INPUT VOLTAGE (V)
0
–10
INPUT CURRENT (mA)
20
2
4
6 8
3973 TA10b
10
40
60
0
10
30
50
12
INPUT CURRENT
DROPOUT
CONDITIONS
FRONT PAGE
APPLICATION
WITH UVLO
PROGRAMMED
TO 6V
FRONT PAGE
APPLICATION
V
OUT
2V/DIV
V
IN
5V/DIV
5ms/DIV
FRONT PAGE APPLICATION
V
IN
= 12V
V
OUT
= 5V
1k INPUT SOURCE RESISTANCE
2.5mA LOAD
3973 TA10c
UVLO PROGRAMMED TO 6V