Datasheet

11
LT1241 Series
U
SA
O
PP
L
IC
AT
ITY
P
I
CA
L
LT1241 • TA01
5V REF
OSCILLATOR
EXTERNAL
SYNC
INPUT
0.01µF
47Ω
C
T
D1
R
T
R
T
/C
T
V
REF
D1 IS REQUIRED IF THE SYNC AMPLITUDE IS LARGE
ENOUGH TO PULL THE BOTTOM OF C
T
MORE THAN
300mV BELOW GROUND.
8
4
+
+
–
+
–
1
2
–
+
3
LT1241 • TA02
R
V
REF
FB
COMP
I
SENSE
C
2.5V
2R
R
1V
1.5V
1mA
5.6V
8
5V REF
+
–
+
–
2
–
+
4
1
8
7
5
6
LT1241 • TA03
FB
COMP
R
T
/C
T
V
REF
V
IN
R
S
R2
C
R1
V
CLAMP
≈
1.67
R2
+ 1

R1
( (
I
PK (MAX)
≈
V
CLAMP 
R
S
WHERE: 0V ≤ V
CLAMP
≤ 1.0V t
SOFT START
= –ln 1 –
V
C
C
R1 R2

3 • V
CLAMP
R1 + R2
I
SENSE
2.5V
2R
R
1V
1.5V
BLANKING
1mA
5.6V
OSCILLATOR
R
S
18V
V
CC
UV
LOCKOUT
GND
OUTPUT
5V REF
MAIN BIAS
REFERENCE PULL-DOWN
OUTPUT
PULL-DOWN
REFERENCE ENABLE
T
3
100k
External Clock Synchronization
Soft Start
Adjustable Clamp Level with Soft Start