Figure 4-15. Ethernet Phy Schematic Example
470R
0402
5%
R
EARTH_ETH
GND_ETH
VDD_3V3
EARTH_ETH
EARTH_ETH
GND
GND_ETH
0R
0402
R
0.1uF
10V
0402
C
0.1uF
10V
0402
C
120R
BLM18PG121SN1D
FB
DIFF100
DIFF100
DIFF100
DIFF100
TD+
TD-
RD-
RD+
TCT
RCT
1nF
75R
75R
75R
75R
TX+
TX-
RX+
RX-
Green
Yellow
1
2
3
4
5
6
7
8
Right
Lift
3
1
2
5
6
4
10
9
8
SH
D
11
12
JD2-0010NL
J
CON RJ-45 JD2-0010NL
ATSAMA5D27-WLSOM1
U1
ETH_TX_N
88
ETH_TX_P
89
ETH_RX_P
87
ETH_RX_N
86
ATSAMA5D27-WLSOM1
U1
ETH_LED0
84
4.3.2.2
Design Layout Recommendations
When designing the Ethernet interface, consider the following recommendations:
• ETH_TX_P, ETH_TX_N, ETH_RX_P and ETH_RX_N should be routed on the top layer without any vias. Traces
must be straight.
• ETH_TX_P and ETH_TX_N should be matched in length to within 120 mils.
• ETH_RX_P and ETH_RX_N should be matched in length to within 120 mils.
• ETH_TX_x and ETH_RX_x must be symmetric.
• Place the TX_P and TX_N signals at least 2 times the trace width away from other signals for noise immunity.
• Place signals at least 2 times the trace width away from any copper plan.
• Place the TX and RX signals at least 5 times the trace width away from other signals for noise immunity.
• Check that the ETH_TX_x and ETH_RX_x line impedance is the same for all signal layers. Recommended
differential impedance for net: 100Ω ± 5%.
4.3.2.3
Design Layout Example
4.4
Voltage Threshold Detector
The Microchip ATSAMA5D27-WLSOM1 embeds a MIC842 micro-power, precision-voltage comparator with an on-
chip voltage reference.
The device is intended for voltage monitoring applications. External resistors are used to set the voltage monitor
threshold. When the threshold is crossed, the outputs switch polarity. Refer to the figures below.
SAMA5D27 Wireless SOM1
Functional Description
©
2021 Microchip Technology Inc.
and its subsidiaries
Complete Datasheet
DS60001590D-page 31
