I noticed that a lot of CAN new test equipment allow you to enable/disable the termination via software. Is there an new transceiver in the market or an accepted way to implement this??
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\$\begingroup\$ You could use an analog switch. See:electronics.stackexchange.com/questions/169933/… \$\endgroup\$– Marko BuršičMay 25, 2016 at 9:19
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\$\begingroup\$ @MarkoBuršič The analog switch will have a dramatic effect on the common-mode range and voltage limits allowed on the bus lines. CAN transceivers are made to be very tolerant regarding this (in case there is a voltage shift between the ground level on the different nodes), and you'll just nullify this by using a simple analog switch. \$\endgroup\$– dimMay 25, 2016 at 11:52
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\$\begingroup\$ @dim Then MAX14759/MAX14761/MAX14763, Maxim that claims their analog switches are good for termination of RS485, CAN,...are liars. \$\endgroup\$– Marko BuršičMay 25, 2016 at 16:29
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\$\begingroup\$ They are above and below the rails analog switch. This is very particular and indeed solves the problem I mentioned. But these are not regular analog switch. \$\endgroup\$– dimMay 25, 2016 at 16:33
1 Answer
This is typically done using a bipolar solid-state relay:
simulate this circuit – Schematic created using CircuitLab