Datasheet
LT3507
27
3507fb
For more information www.linear.com/LT3507
typical applications
15V, 1.8V and 1.2V 2-Stage Step Down
V
IN1
BOOST1 UVLO
OVLO
PGOOD2
PGOOD3
BOOST 2
SW2
FB2
V
C2
BOOST3
SW3
FB3
TRK/SS2
TRK/SS3
PGOOD1
SW1
FB1
V
C1
TRK/SS1
BIAS
0.1µF
22µF
D1
68.1k
31.6k
220pF
0.01µF
187k
L1 10µH
V
OUT1
15V
0.4A
V
BST
3V
V
IN
21V TO 36V
L2 3.3µH
V
IN2
V
IN3
V
INSW
49.9k 3.4k
UVLO = 19V
11.5k
10.5k
10µF
DRIVE
FB4
TRK/SS4
R
T
/SYNC
V
C3
GND
LT3507
RUN1
RUN2
RUN3
0.1µF
33µF
PGOOD
V
BST
D2
13.3k
SHDN
1000pF
D1: DIODES, INC. B140A
D2, D3: DIODES, INC. B240A
L1: TDK LTF5022T-100M1R4
L2: TDK VLCF5020T-3R3N2R0-1
L3: TDK VLCF5020T-2R2N1R7
Q1: DIODES INC. BC817-16
18.2k
100k
3507 TA04
54.9k
f
SW
= 800kHz
V
OUT2
1.8V
1.5A
22.6k
V
OUT2
L3 2.2µH
0.1µF
47µF
V
BST
D3
12.7k
1000pF
30.1k
270pF
2.2µF
Q1
V
OUT3
1.2V
1.5A
15.0k
Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.Downloaded from Arrow.com.