Datasheet

LT3991/LT3991-3.3/LT3991-5
20
3991fa
Typical applicaTions
3.3V Step-Down Converter with Undervoltage Lockout, Soft-Start, and Power Good
10pF
SW
FB
SS
RT
V
IN
V
IN
6V TO 55V
V
OUT
3.3V
1.2A
4.7µF
0.47µF
47µF
562k
118k
10µH
1M
GND
PG
PGOOD
SYNC
LT3991
3991 TA06
EN
BOOST
BD
150k
5M
1M
100k
1nF
f = 400kHz
12V Step-Down Converter
10pF
SW
FB
SS
RT
V
IN
V
IN
16V TO 55V
V
OUT
12V
1.2A
10µF
0.47µF
10µF
110k
49.9k
f = 800kHz
10µH
1M
GND
BD
SYNC
OFF ON
LT3991
3991 TA06
EN BOOST
PG
1.8V Step-Down Converter
10pF
SW
FB
SS
RT
V
IN
V
IN
4.3V TO 37V
V
OUT
1.8V
1.2A
4.7µF
0.47µF
100µF
1M
162k
f = 300kHz
6.8µH
511k
GND
SYNC
OFF ON
LT3991
3991 TA05
EN BOOST
PG
BD