Datasheet

LT3751
9
3751fc
block DiagraM
+
FB
CSN
CSP
LVGATE
HVGATE
CLAMP
3751 BD
START-UP
ONE-SHOT
CHARGE
V
CC
OTLO
MASTER
LATCH
S
Q
R
Q
ENABLE
GATE
DRIVER
ONOFF
DONE
FAULT
100k
10µF
100k
S
Q
R
Q
V
CC
12V
INTERNAL
UVLO
3.8V
V
CC
–
+
+
–
–
+
+
–
–
+
55V
55V
UVLO1
OVLO1
UVLO2
OVLO2
55V
55V
R
UVLO1
191k
R
UVLO2
191k
R
OVLO1
240k
R
OVLO2
240k
1.22V
REFERENCE
UVLO/OVLO
COMPARATORS
R
BG
1.33k
GND RBG
TO V
OUT
COMPARATOR
V
OUT
COMPARATOR
–
+
DCM
ONE-SHOT
–
+
DCM
COMPARATOR
26kHz ONE-SHOT
CLOCK
S
R
Q
Q
COUNTER
26kHz
ONE-SHOT
CLOCK
SWITCH
LATCH
0.98V
REFERENCE
DIFF. AMP
COMPARATOR
WITH
INTERNAL
60V CLAMPS
1.22V
REFERENCE
GATE DRIVE
CIRCUITRY
60V
RV
OUT
60V
RDCM
–
+
–
+
–
+
RESET
CLK
COUNT
+
–
+
–
TIMING AND PEAK
CURRENT CONTROL
–
+
26kHz
ONE-SHOT
CLOCK
MODE
CONTROL
DIE
TEMP
160ºC
1.22V
REFERENCE
•
•
60V
RV
OUT
40.2k
R
DCM
18.2k
M1
V
CC
R
SENSE
12mΩ
ERROR
AMP
A1
11mV TO 106mV
MODULATION
106mV
162mV
RV
TRANS
RV
TRANS
40.2k
10µF
47µF
×2
D1
T1
1:10
PRIMARY
SECONDARY
+
V
OUT
450V
C
OUT
R
FBH
3.65M
R
FBL
10k
V
TRANS
12V
V
TRANS
V
CC
TO CHARGE
ONE-SHOT
V
CC
V
CC
V
DRAIN
10nF
AUXILIARY
MAIN
FAULT
LATCH