On-Module Trace Lengths and Impedance¶

LVDS FPGA IO Pairs¶

The LVDS pairs (i.e. B3B_RX_B34n and B3B_RX_B34p) are matched length, generally better than 10 mils and many times much tighter than that, at the edge connector.

In cases where specific lengths need to be known between multiple pairs (such as an FPGA Ethernet interface) we are happy to provide the necessary data for those specific pins. Please contact us.

The LVDS pairs are routed as loosely coupled pairs with 100 ohm impedance and if used as single-ended signals, the impedance is about 50ohm.

HPS Ethernet Pins¶

The RGMII signals are around 3 inches in length on the MitySOM. All TX (RGMII1_TX_CTL/CLK/TXD0/TXD1/TXD2/TXD3) signals are matched in length to each other and all RX (RGMII1_RX_CTL/CLK/RXD0/RXD1/RXD2/RXD3) signals are matched length to each other. For best results, keep the RGMII traces less than 2 inches in length and continue the length matching to the Phy on your carrier board.

The RGMII signals are 50 ohm impedance for the TX group and the RX group of signals.