Rainbow Electronics MAX5953D - Manual (Page 20)

MAX5953A/MAX5953B/MAX5953C/MAX5953D
IEEE 802.3af PD Interface and PWM Controllers
with Integrated Power MOSFETs
20 ______________________________________________________________________________________
PGOOD PGOOD
U1
R9
14.7k
Ω
R8
316k
Ω
V+
R1
(R
DISC
)
25.5k
Ω
C2
22
µ F
63V
C1
68nF
R3
210k
Ω
C3
100pF
C6
150pF
C7 100pF
C8 0.022
µ F
PGOOD
D1 60V
-48V
RT
N
-48V
0.5A
R2
(R
RCLASS
)
255
Ω
C5
4700pF
C4
2.2
µ
F
R4
26.7k
Ω
R6 100k
Ω
R5 1k
Ω
4 8
RCLASS
18
DCUVLO 37
HVIN 39
DRNH
PPWM
BST
33, 34
21
36
XFRMRH
31, 32
XFRMRL
28, 29
INBIAS
40
D4
V EE
10
RCFF
44
RAMP
45
DRVIN
30
GA
TE
9
OUT
16
REGOUT
FL
TINT
43
42
24
R
TCT
CSS
22
GND
25
OPTO
41
23
PGND
PGND
C9 OPEN
C13 1µ
F
R10 OPEN
R13 14.3k
Ω
R11 6.81k
Ω
R12 1.78k
Ω
R7
3.9k
Ω
L1
220
µ H
C10 0.022
µ F
C16 0.01
µ F
C14 0.15
µ
F
C11 22
µ
F
C12 1µ
F
20
CS
26, 27
TL431CD
SRC
R16 4.99k
Ω
C15 0.03
µ F
OUT 12V
, 0.75A
GND
MAX5953A
Figure 7. PD with Nonisolated Step-Down (Buck) Converter