Datasheet

LTC4257-1
15
42571fb
APPLICATIO S I FOR ATIO
WUUU
Figure 9. Auxiliary Power Source for PD
RX
–
6
RX
+
3
TX
–
2
TX
+
RJ45
T1
1
7
8
5
4
SPARE
–
+
–
SPARE
+
ISOLATED
WALL
TRANSFORMER
TO PHY
GND
8
45
OPTION 1: AUXILARY POWER INSERTED BEFORE LTC4257-1
OPTION 2: AUXILARY POWER INSERTED AFTER LTC4257-1 WITH SIGNATURE DISABLED
V
IN
V
OUT
38V TO 57V
D8
S1B
D3
SMAJ58A
TVS
C1
PD
LOAD
C14
0.1µF
100V
RX
–
6
RX
+
3
TX
–
2
TX
+
RJ45
T1
1
7
8
5
4
SPARE
–
+
–
SPARE
+
ISOLATED
WALL
TRANSFORMER
TO PHY
GND
SIGDISA
LTC4257-1
LTC4257-1
BR2
DF01SA
~
~
+
–
BR1
DF01SA
~
~
+
–
BR1
DF01SA
~
~
+
–
8
7
45
V
IN
V
OUT
42571 F09
D10
S1B
D3
SMAJ58A
TVS
C1
100k
PD
LOAD
D9
S1B
OPTION 3: AUXILARY POWER APPLIED TO LTC4257-1 AND PD LOAD
RX
–
6
RX
+
3
TX
–
2
TX
+
RJ45
T1
1
7
8
5
4
SPARE
–
+
–
SPARE
+
ISOLATED
WALL
TRANSFORMER
TO PHY
38V TO 57V
GND
LTC4257-1
8
45
V
IN
V
OUT
D10
S1B
D3
SMAJ58A
TVS
C1
PD
LOAD
C14
0.1µF
100V
C14
0.1µF
100V
BR2
DF01SA
~
~
+
–
BR1
DF01SA
~
~
+
–
BR2
DF01SA
~
~
+
–
100k
BSS63