Datasheet

LTC3728
10
3728fg
FUNCTIONAL DIAGRAM
SWITCH
LOGIC
–
+
0.8V
4.7V
5V
V
IN
V
IN
4.5V
BINH
CLK2
CLK1
0.18μA
R6
R5
+
–
FCB
+
–
–
+
–
+
–
+
V
REF
INTERNAL
SUPPLY
3.3V
OUT
V
SEC
R
LP
C
LP
1.5V
FCB
EXTV
CC
INTV
CC
SGND
+
5V
LDO
REG
SW
SHDN
0.55V
TOP
BOOST
TG
C
B
C
IN
D
1
D
B
PGND
BOT
BG
INTV
CC
INTV
CC
V
IN
+
C
SEC
C
OUT
V
OUT
3728
FD/F02
D
SEC
R
SENSE
R2
+
+
V
OSENSE
DROP
OUT
DET
RUN
SOFT
START
BOT
TOP ON
S
R
Q
Q
OSCILLATOR
PHASE DET
PLLFLTR
PLLIN
FCB
EA
0.86V
0.80V
OV
V
FB
1.2μA
6V
R1
–
+
R
C
4(V
FB
)
RST
SHDN
RUN/SS
I
TH
C
C
C
C2
C
SS
4(V
FB
)
0.86V
SLOPE
COMP
3mV
+
–
–
+
SENSE
–
SENSE
+
INTV
CC
30k
45k
2.4V
45k
30k
I1 I2
B
DUPLICATE FOR SECOND
CONTROLLER CHANNEL
+– –+
50k
F
IN
+
–
+
–
+
–
+
–
PGOOD
V
OSENSE1
V
OSENSE2
0.86V
0.74V
0.86V
0.74V
Figure 2