ltc4268cdkd-1-trpbf Linear Technology Corporation, ltc4268cdkd-1-trpbf Datasheet - Page 24

• Manufacturer Part Number: ltc4268cdkd-1-trpbf
• Description: High Power Pd With Synchronous Noopto Flyback Controller
• Manufacturer: Linear Technology Corporation

LTC4268-1
APPLICATIONS INFORMATION
24
RJ45
RJ45
RJ45
RJ45
1
2
3
6
4
5
7
8
1
2
3
6
4
5
7
8
1
2
3
6
4
5
7
8
1
2
3
6
4
5
7
8
TX
TX
RX
RX
TX
TX
RX
RX
TX
TX
RX
RX
TX
TX
RX
RX
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
SPARE
+
–
+
–
+
–
+
–
TRANSFORMER
TRANSFORMER
TRANSFORMER
TRANSFORMER
ISOLATED
ISOLATED
ISOLATED
ISOLATED
WALL
WALL
WALL
WALL
T1
T1
T1
T1
OPTION 3: AUXILIARY POWER APPLIED TO LTC4268-1 AND PD LOAD
OPTION 2: AUXILIARY POWER INSERTED AFTER LTC4268-1 WITH SIGNATURE DISABLED
OPTION 1: AUXILIARY POWER INSERTED BEFORE LTC4268-1
+
V
–
+
V
–
+
V
–
+
V
–
WW
WW
WW
WW
TO PHY
TO PHY
TO PHY
TO PHY
Figure 10. Interfacing Auxiliary Power Source to the PD
OPTION 4: AUXILIARY POWER APPLIED TO ISOLATED LOAD
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
~
BR1
BR2
BR1
BR2
BR1
BR2
BR1
BR2
+
–
+
–
+
–
+
–
+
–
+
–
+
–
+
–
S1B
D8
D3
SMAJ58A
TVS
D3
SMAJ58A
TVS
D3
SMAJ58A
TVS
D3
SMAJ58A
TVS
0.1μF
4.7k
100k
100V
C14
V
V
LTC4268-1
PORTN
LTC4268-1
PORTN
BSS63
V
V
PORTP
PORTP
V
V
C14
0.1μF
100V
NEG
C14
0.1μF
100V
C14
0.1μF
100V
NEG
SHDN
V
LTC4268-1
PORTN
D10
S1B
SHDN
V
V
LTC4268-1
PORTN
PORTP
V
+
NEG
V
+
PORTP
V
GND
C1
NEG
PG
C1
S1B
D10
S1B
D9
V
IN
+
V
+
IN
• 42V ≤ V
• NO POWER PRIORITY ISSUES
• NO LTC4268-1 CURRENT LIMITS FOR V
• 42V ≤ V
• NO POWER PRIORITY ISSUES
• LTC4268-1 CURRENT LIMITS FOR BOTH PoE AND V
• V
• REQUIRES EXTRA DIODE
• SEE APPS REGARDING POWER PRIORITY
C1
C1
WW
DRIVE
WW
ANY VOLTAGE BASED ON PD LOAD
V
WW
IN
ISOLATED DC/DC CONVERTER
≤ 57V
≤ 57V
• V
• SEE APPS REGARDING POWER PRIORITY
• BEST ISOLATION
WW
LOAD
ANY VOLTAGE BASED ON PD LOAD
WW
WW
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