Shielded Gigabit Ethernet Port for Board-Level Integration
The Molex 0857931020 is a single-port RJ45 jack from the 85793 series, designed for 10/100/1000 Base-T and AutoMDIX applications. It is a right-angle, through-hole mounted connector with a shielded stainless steel shell and integrated EMI fingers that provide a low-impedance ground path to the chassis panel.
The through-hole solder termination requires plated through-holes in the PCB footprint; the board lock adds two additional plated holes for mechanical retention. The shielded shell with EMI fingers means the PCB layout should include a ground plane connection to the shell pins and a chassis ground pad where the fingers contact the panel cutout — this is critical for meeting FCC/EMC radiated emissions limits on a 1000 Base-T port.
Signal Integrity for 1000 Base-T
Rated for 10/100/1000 Base-T and AutoMDIX, this jack is specified for the 4 differential pair signaling used in Gigabit Ethernet over twisted pair. The shielded construction and EMI fingers help contain common-mode noise and reduce crosstalk between the pairs within the connector.
The part is packaged in trays, which is standard for through-hole RJ45 jacks in production volumes.