EQCO850SC.3-HS Datasheet, PDF (9/24 Pages) Microchip Technology – Pb-Free and RoHS Compliant

EQCO850SC.3-HS/EQCO875SC.3-HS
FIGURE 3-3:
RECOMMENDED LAYOUT
The ground layout of the EQCO850SC.3-HS is critical
to the EMC and EMI performance of the circuit. The
AGND connection should be made directly to the body
of the connector as shown in Figure 3-2. It should not
be connected directly to the GND tab of the chip.
Similarly, AVCC should be decoupled directly to the
connector body (see position of C5). The termination
resistor (R1 in Figure 3-2 and Figure 3-3) must have its
ground connection at the connector body and C7, and
the connection between R1 and the connector must be
kept as short as possible. The impedance of all the
traces must be well-controlled, including on the
connector itself.
The SDIp/SDIn and SDOp/SDOn differential traces
should be matched in length to minimize time of arrival
skew. For traces longer than a few millimeters, the
impedance of the differential transmit and receive
signals should be laid out as 100Ω differential traces
and the termination to the PHY should be placed close
to the PHY, not to the EQCO850SC.3-HS.
Microchip can design a PCB layout capable of
maximum cable length for any combination of
impedance system (50Ω or 75Ω) and coax connector
(SMA, BNC, DIN, SMB, etc.) on request.
 2010-2015 Microchip Technology Inc.
DS60001313A-page 9