LTC4269-1_15 Datasheet, PDF (40/44 Pages) Linear Technology – IEEE 802.3at PD with Synchronous No-Opto Flyback Controller

LTC4269-1
TYPICAL APPLICATIONS
PoE-Based 12V, 2A Power Supply
48V AUXILIARY
POWER
B1100 × 8 PLCS
54V FROM
DATA PAIR
S1B
V_PORTP
107k
36V
PDZ36B
10k
BSS63LT1 383k
S1B
14.0k
10μH
+
10μF
2.2μF
BAS21
29.4k
20Ω
3.01k
20k
+
22μF
1μF
T1
t
tt
150Ω
47pF
0.33μH
12V
2A
10μF
C1
47μF
FDS2582
15Ω
470pF
FDS3572
54V FROM
SPARE PAIR
10Ω
SMAJ58A
0.1μF
100V
30.9Ω
24k
UVLO
V_PORTP
SHDN
R_CLASS
PWRGD
FB V_CC
LTC4269-1
PG
SENSE⁺
SENSE^–
SG
V_PORTN
V_NEG SYNC GND
OSC PGDLY t_ON ENDLY R_CMP C_CMP
V_CMP
2.2nF
2kV
33mΩ
MMBT3906 MMBT3904
100Ω
1μF
15Ω
2.2nF
T2
T1: PCA ELECTRONICS, EPC3410G-LF
OR
PULSE, PA2467NL
T2: PULSE, PE-68386NL
C1: PSLDIC476MH
B1100
33pF
100k
0.1μF
tt
10k
12k
38.3k 2.2k
1nF
4.7nF
BAT54 10k
42691 TA04a
Efficiency
93
91
89
42V_IN
87
85
57V_IN
48V_IN
83
81
79
77
75
73
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
42691 TA04b
Regulation
12.5
12.4
12.3
12.2
50V_IN
12.1
42V_IN
12.0
57V_IN
11.9
11.8
11.7
11.6
11.5
0.2 0.38 0.56 0.74 0.92 1.1 1.3 1.5 1.6 1.8 2
LOAD CURRENT (A)
42691 TA04c
42691fc
40