Sorry.

Thats a National doc.  App Note AN-1057

Also look at TI doc SLLA036  Design Notes for TIA/EIA-485 interface circuits

Shawn

-----Original Message-----
From: Shawn Yates
Sent: Tuesday, February 13, 2001 1:58 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: [EE]: RS485 input


Look for a TI document called 10 ways to bullet proof RS485.

Also, I took to using SN75LBC184P, which is a 1/2 unit (so you can have
twice as many on the line) and has built in TVS's up to 1K5.

HTH

Shawn

-----Original Message-----
From: Edson Brusque [mailto:ebrusque@TERRA.COM.BR]
Sent: Tuesday, February 13, 2001 2:14 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: [EE]: RS485 input


Hello,

    I'm using a 75176 to make the RS485 inputs on my projects. I want to
know if I could use a 74LS04 or other similar chip to make the input.

    The 75176 input is of a higher impedance than the 74LS04? Using a 74LS04
could cause disturbs on the RS485 line?

    How is the best way to connect a 75176? Should I connect the 75176 pins
direct on the RS485 line as:

                            +-----
              RS485 (data)--|
        RS485 (complement)--|75176
            RS485 (ground)--|
                            +-----

    or use some sort of protection like current limiting resistors?

    Thank you very much,

    Brusque

-----------------------------------
Edson Brusque
Research and Development
C.I.Tronics Lighting Designers Ltda
(47) 323-2685  /  (47) 9993-6453
Blumenau  -  SC  -  Brazil
www.citronics.com.br
-----------------------------------

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.