8
LT1725
1725fa
TI I G DIAGRA
UWW
V
SW
VOLTAGE
V
IN
GND
OFF ON
MINIMUM t
ON
ENABLE DELAY
MINIMUM ENABLE TIME
1725 TD
OFF ON
SWITCH
STATE
FLYBACK AMP
STATE
0.80×
V
FLBK
V
FLBK
COLLAPSE
DETECT
ENABLEDDISABLED DISABLED
FLYBACK ERROR A PLIFIER
W
+
–
D1
•
•
•
T1
ISOLATED
V
OUT
C1
M1
+
V
IN
V
C
C2
R2
R1
FB
V
BG
Q1 Q2
I
I
M
I
M
I
FXD
ENAB
1725 EA
