Datasheet

LTC3421
7
3421f
BLOCK DIAGRA
W
Σ
+
–
+
–
+
–
+
PWM
LOGIC
CURRENT
COMP
ERROR
AMP
1.22V
CURRENT
LIMIT
++
Burst Mode
CONTROL
THERMAL
REG/SHDN
OSC
1.22V REF
2%
SLEEP
1%
UV
OV
OFF
–3%
0.97V/1.05V
BURST
I/3000
3%
GND
–
+
–
+
–
+
BURST
COMP
9
LBO
3421 BD
22
V
C
24
FB
1
I
LIM
SS
I
SENSE
AMP
NMOS
ANTICROSS
CONDUCTION
I
LIMIT
=
150k/R
C1
V
IN
V
DD
ANTIRING
–
+
V
IN
WELL
SWITCH
I
ZERO
AMP
C
P
C
SS
R
Z
R2
R1
V
OUT
2.40V TO 5.25V
R
C1
8
V
OUT
17
V
OUT
19
V
OUT
20
6
SW
14
V
IN
1V TO 4.5V
21
ENB
V
OUT
4
V
REF
3
R
T
5
SYNC
V
IN
V
OUT
SYNC
IN
0.6V/
0.63V
7
LBI
R2
ENB
23
10
SHDN
SHUTDOWN
2
SW
15
SW
PMOS
16
V
OUTS
18
PGND
11
EXPOSED
PAD
25
PGND
12
PGND
13
SLOPE COMP
R1
–
+