DS92LX1621: DOUT+ - differential pair tarce impedance

Alan Chang

Part Number: DS92LX1621
Other Parts Discussed in Thread: DS92LX1622

Hi,

on data sheet, 100 ohm differential impedance, does it request differential pair trace impednace of OUT+/- pins control at 100ohm on layout?

if the chip is put near connector, and external cable to DS92LX1622, which impedance should I control to 100 ohm? cable or total (trace layout on PCB + connector + cable+...)?

over 2 years ago

0 Gil Abarca Ramos over 2 years ago

TI__Genius 15230 points

Hi Alan,

The channel link III interface must have a differential impedance of 100 Ohms. The datasheet recommends to use cables and connectors that have matched impedance meaning the Channel link traces, connector and cable must be 100Ohm impedance regardless of the position chip.

Best Regards,

Gil Abarca

0 Alan Chang over 2 years ago in reply to Gil Abarca Ramos

TI__Intellectual 2430 points

Hi Gil,

If this is FR4 PCB layout, TX and RX are on the board, example, right side to left side on board, DOUT +/- differential pair trace on board.

So I should route the differential trace impedance at 100 ohm each trace? Or 100 ohm = (DOUT +) – (DOUT-)? In case of without cable and connector.

0 Gil Abarca Ramos over 2 years ago in reply to Alan Chang

TI__Genius 15230 points

Hi Alan,

The channel link III interface must have a differential impedance of 100 Ohms. The differential impedance is dependent on different factors such as Trace width, trace separation, trace thickness, dielectric thickness, and dielectric constant. If you change one of these factors the impedance will change.

Best Regards,

Gil Abarca

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DS92LX1621: DOUT+ - differential pair tarce impedance