UG-1677
Rev. 0 | Page 5 of 12
To maximize the margin to the EN 55032 Class B specification,
adhere to the following guidelines:
Ensure that the decoupling capacitors are placed as close to
the corresponding
pins as possible.
Place a 10 μF capacitor (C4) and a 0.1 μF capacitor (C5)
between the V
CC
pin and GND
1
pins of the
Place a 0.1 μF capacitor (C7) between the V
IO
pin and
GND
1
pins of the
Connect Pin 24, Pin 26, and Pin 28 of the
together to form a single GND
ISO
net. Connect this net to the
GND
2
pins through the E1 ferrite bead.
Place a 0.1 μF capacitor (C9) between the V
ISOOUT
supply pin
and the GND
ISO
net of the
Connect the V
ISOOUT
pin to the V
ISOIN
pin of the
through the E2 ferrite bead.
Place a 10 μF capacitor (C12) and a 0.1 μF capacitor (C8)
between the V
ISOIN
supply pin (Pin 23) and the GND
2
pins
(Pin 22) of the
Remove any metal planes or floods from the area around
or under the GND
ISO
net and V
ISOOUT
net.
The EVAL-ADM2867EEBZ designed according to these
guidelines meets the EN 55032 Class B requirements with
margin. See Figure 2, Figure 7, and Figure 8 for further details
on the recommended PCB layout.
Figure 2. Layout Guidelines to Achieve EN 55032 Class B
EN 55032 RADIATED EMISSIONS TEST RESULTS
The EVAL-ADM2867EEBZ meets the EN 55032 and CISPR32
Class B requirements for radiated emissions with margin. The
testing was performed in worst case conditions under a full
54 Ω load with both the transceiver and receiver transmitting
at 25 Mbps. Figure 3 shows the results obtained in a 10 meter,
semianechoic chamber, which are below the Class B limit.
Figure 3. CISPR32/EN 55032 Radiated Emissions Test
Table 2. Jumper Configurations
Link Jumper
Connection Description
LK1 A
Connects the RE input of the
to the V
IO
pin. This setting disables the receiver.
B
Connects the RE input of the
to the RE terminal on the P2 connector.
C
Connects the RE input of the
to the GND
1
pins. This setting enables the receiver.
LK2
A
Connects the DE input of the
to the V
IO
pin. This setting enables the driver.
B
Connects the DE input of the
to the DE terminal on the P2 connector.
C
Connects the DE input of the
to the GND
1
pins. This setting disables the driver.
D
Connects the DE input of the
to the RE input signal. Therefore, the input for both RE and DE
is set by the LK1 jumper. This setting ensures that when the driver is enabled, the receiver is disabled, or
when the driver is disabled, the receiver is enabled.
LK3
AB
Connects the TxD input of the
and J1 SMA connector to the TxD terminal on the P3 connector.
BC
Connects the TxD input of the
oscillator output.
To configure the oscillator frequency to be between 1 kHz and 12.5 MHz, set the R2 and R3 resistors.
Only use this option when the V
IO
supply input is between 3 V to 5.5 V.
Not inserted
Connects the TxD input of the
to the J1 SMA connector.
LK4
A
Connects the INVD input of the
to the V
IO
pin. This setting enables the driver inversion feature.
B
Connects the INVD input of the
to the INVD terminal on the P3 connector.
C
Connects the INVD input of the
1
pins. This setting is used for normal driver operation.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
GND
1
GND
1
V
CC
V
IO
GND
1
GND
1
GND
1
10µF
0.1µF
0.1µF
V
SEL
GND
ISO
V
ISOOUT
GND
2
V
ISOIN
GND
ISO
RxD
RE
DE
INVR
GND
1
INVD
TxD
GND
2
A
B
GND
2
GND
2
Y
Z
GND
ISO
METAL KEEP OUT
ADM2867E
TOP VIEW
(Not to Scale)
0.1µF
10µF
E1
E2
0.1µF
220
60-
002
80
70
60
50
40
30
20
10
0
RA
DI
A
TE
D
FIE
LD
S
TR
E
N
G
TH
(
dB
µ
V
/m
)
30
100
FREQUENCY (MHz)
1000
CLASS B
CLASS A
22060-
009
