SN65LBC180, Rise time, RS485

Joseph Hessel

Other Parts Discussed in Thread: SN65LBC180, SN65LBC184

I am currently using the SN65LBC180 with RS485. I need to know what the specs of the SN65LBC180 are for use of RS485 signals. I specifically need to know the tr (Rise Time) of a RS485 signal.

The data sheet does not list this value and I am wondering if when the SN65LBC180 is used with RS485, if its charecteristics and specs are simular to the SN65LBC184

Thank you.

over 13 years ago

0 Avi Chami1 over 13 years ago

Mastermind 7395 points

Look at page 5, switching characteristics table, illustrated at figure 6. trise is 5ns typ, 8ns max

0 Thomas Kugelstadt over 13 years ago

TI__Mastermind 28265 points

Unfortunately the driver single-ended rise times are not provided in the data sheet but the transition time of the differential output signal t _t(OD) is specified with min, typ, and max. values on page 4 (under the driver switching characteristics). The transition time can range from as little as 5ns to as much as 20ns. The SN65LBC180 is therefore a much faster device than the SN65LBC184.

Regards, Thomas

0 Avi Chami1 over 13 years ago in reply to Thomas Kugelstadt

Mastermind 7395 points

Oops, sorry, my answer was wrong, tr I wrote is for the 485 to single ended side. Thomas answer is the correct one.

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SN65LBC180, Rise time, RS485