
Shanghai ZLAN Information Technology Co., Ltd Tel: +86-17321037177 http://www.zlmcu.com
25
Figure 15 Part Circuit of SNMP Card Power Supply
When using ZLAN1003, if it is more than 5V voltage input, it is recommended to use
the DC-DC circuit instead of the LDO chip with low energy conversion efficiency.
Here take the example of MC34063 to introduce. The input voltage can be 9V~24V.
MC34063 converts the input voltage to 3.3V and then convert to 1.8V through
lm1117-1.8 to supply power to the chip.
Figure 16 SNMP Card Network Part
The network part is composed of a network transformer PM44_11BG and the RJ45
with the Ethernet port light, and four resistance of 1% precision.
3.3 High speed and low speed selection
C9
0.1uF
D1
1N4004
R8
1.2K 1%
C10
0.1uF
D2
1N5819
C8
100uF/35V
C11
100uF/16V
TC
3
SC
1
SE
2
G
N
D
4
FB
5
V CC
6
IPK
7
D
RI
8
U4
MC34063
L1
220uH
R7
2K 1%
C12
470PF
C15
0.1uF
C14
0.1uF
IN
3
G
N
D
1
O UT
2
U6
LM1117-1.8
C16
47uF/16V
V CC 1 8
V CC 3 3
G ND G ND
G ND G ND
G ND
G ND
G ND G ND
V CC 3 3
V CC 1 2
TXOP1
TXOM1
RXIP1
RXIM1
NET_RX-
NET_TX-
TXOM1
RXIM1
RXIP1
TXOP1
LINK
ACT
VCC33
VCC33
C13
0.1uF
R19
49.9 1%
R15
75
R12
49.9 1%
R14
75
R11
49.9 1%
R21
1K
R16
75
C18
0.1uF
C17
0.1uF
3
1
2
4
8
7
6
5
14
13
12
11
10
9
15
16
U5
PM44_11BG
R22
1K
R13
75
TXP
3
RXP
1
RXM
2
CM1
4
CM4
8
CM3
7
TXM
6
CM2
5
GRE-
9
GRE+
10
YE L+
11
YE L-
12
J5
RJ45
R17
49.9 1%
VCC33