Datasheet

LTC3708
9
3708fb
FUNCTIONAL DIAGRAM
CLOCK DETECTOR
FCB
INTLPF
I
ON
R
ON
EXTLPF
PHASE DETECTOR
(PD1)
TO CHANNEL 2 OST
FCNT
ON
SHDN
OV
ENABLE
PHASE DETECTOR
(PD2)
OST
FROM CHANNEL 2
TG
t
ON
= (10pF)
0.7
I
ION
R
S
20k
Q
–
+
–
+
–
+
–
+
–
+
I
CMP
I
REV
TG
C
B
M1
L1
V
IN
D
B
V
OUT
+
C
IN
SWITCH
LOGIC
SW
SENSE
+
DRV
CC
BG
PGND
SENSE
–
0.66V
0.54V
FROM CHANNEL 2
OV AND UV COMPARATORS
V
FB
R2
SGND
BOOST
M2
V
CC
C
VCC
0.6V
REF
C
DRVCC
+
C
OUT
R1
PGOOD
OV
UV
RUN
SHDN
ENABLE
>100μs
BLANKING
V
RNG
1.4V
0.7V
I
TH
C
C
R
C
TRACK
Q4
EA
3.3μA
s
1
240k
Q1 Q2 Q30.6V
V
REF
DUPLICATE FOR SECOND
CHANNEL CONTROLLER
NOTE: THE RUN/SS PIN ONLY CLAMPS
V
REF
FOR PHASE 1 NOT PHASE 2.
+
–
+
–
1.3V
RUN/SS
1.2μA
6V
3708 FD
C
SS
1.3V
C
EPLL
R
EPLL
R
IPLL
C
IPLL