Datasheet

LTC3729
9
3729fb
FUNCTIONAL DIAGRAM
SWITCH
LOGIC
0.80V
4.7V
5V
V
IN
V
IN
CLK2
CLK1
+
–
–
+
V
REF
PHASE LOGIC
INTERNAL
SUPPLY
PHASMD
±2µA
EXTV
CC
INTV
CC
SGND
+
5V
LDO
REG
SW
SHDN
TOP
BOOST
TG
C
B
C
IN
D
B
PGND
BOT
BG
INTV
CC
INTV
CC
V
IN
+
V
OUT
3729 FBD
R1
EAIN
DROP
OUT
DET
RUN
SOFT
START
BOT FCB
FORCE BOT
S
R
Q
Q
OSCILLATOR
PLLLPF
50k
EA
0.86V
0.80V
OV
1.2µA
6V
R2
–
+
R
C
4(V
FB
)
RST
SHDN
RUN/SS
I
TH
C
C
C
SS
4(V
FB
)
0.86V
SLOPE
COMP
+
–
SENSE
–
SENSE
+
INTV
CC
30k
45k
2.4V
45k
30k
I1
PHASE DET
PLLIN
CLKOUT
DUPLICATE FOR SECOND
CONTROLLER CHANNEL
+–
R
SENSE
L
C
OUT
+
F
IN
R
LP
C
LP
0.74V
0.86V
A1
+
–
DIFFOUT
V
OS
+
V
OS
–
40k 40k
40k 40k
+
–
+
–
EAIN
PGOOD
PIN FUNCTIONS
G Package/UH Package
EXTV
CC
(Pin 22/Pin 21): External Power Input to an
Internal Switch . This switch closes and supplies INTV
CC
,
bypassing the internal low dropout regulator whenever
EXTV
CC
is higher than 4.7V. See EXTV
CC
Connection in
the Applications Information section. Do not exceed 7V
on this pin and ensure V
EXTVCC
≤ V
INTVCC
.
V
IN
(Pin 24/Pin 23): Main Supply Pin. Should be closely
decoupled to the IC’s signal ground pin.
CLKOUT (Pin 28/Pin 27): Output Clock Signal available
to daisychain other controller ICs for additional MOSFET
driver stages/phases.