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'Another MAX232 question'
1998\03\04@122946 by Calvin

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In the MAX232 datasheet they indicate 1uF caps for the charge pump, but they
also show 0.1uF caps in parenthesis. As I understand it they mean that I can
still use it with the 0.1uF caps, but only achieve a lower speed; am I
right?
BTW, I could not find any info about the parenthesis values on the
datasheet.

TIA

Calvin

{Original Message removed}

1998\03\04@124933 by SHAWN ELLIS

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> In the MAX232 datasheet they indicate 1uF caps for the charge pump, but they
> also show 0.1uF caps in parenthesis. As I understand it they mean that I can
> still use it with the 0.1uF caps, but only achieve a lower speed; am I
> right?
> BTW, I could not find any info about the parenthesis values on the
> datasheet.
>
> TIA
>
> Calvin
>
The only way I ever got this to work was with .1uf caps.

1998\03\04@152702 by DREITEK

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In a message dated 98-03-04 12:50:22 EST, you write:

<<
> In the MAX232 datasheet they indicate 1uF caps for the charge pump, but
they
> also show 0.1uF caps in parenthesis. As I understand it they mean that I
can
> still use it with the 0.1uF caps, but only achieve a lower speed; am I
> right?
> BTW, I could not find any info about the parenthesis values on the
> datasheet.
>
> TIA
>
> Calvin
>
The only way I ever got this to work was with .1uf caps.

 >>
Hello,

Use a MAX233 and forget the caps all together!

Dave Duley

1998\03\04@160012 by Brian Schousek

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   Looking at the max23x datasheet I've got on my hard-drive(doc 19-4323;
Rev 6; 3/96) page 1 shows the max 232 1u (.1u) capacitors and in the Data
Rate (kbps) column it shows 120 (64) I would take this to mean that the 232
can do 120 kbps w/1u and 64 kbps w/.1u.
   The '232A is shown as achieving 200 kbps with .1u caps. I assume this
means the 232A charge pump operates at a higher frequency.
   To bring another thread into this, note that the acronym kbps is
ambiguous. Could be kilobits, could be kilobytes. Only by looking further
into the data sheet do we see kbits/sec spelled out. Therefore the 232 is
capable of 64000/(8+1+1)->6400 baud with .1u caps.

Brian

{Original Message removed}

1998\03\04@171441 by Alessandro Zummo

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Il 04-Mar-98, Calvin scrisse:


> In the MAX232 datasheet they indicate 1uF caps for the charge pump, but they
> also show 0.1uF caps in parenthesis. As I understand it they mean that I can
> still use it with the 0.1uF caps, but only achieve a lower speed; am I
> right?
> BTW, I could not find any info about the parenthesis values on the
> datasheet.

The datasheet says:

MAX232 (MAX202)     1.0 (0.1)

Maybe the value in parenthesisi is referred to MAX202?

--

  - *Alex* -

 http://freepage.logicom.it/azummo/

1998\03\04@204849 by Richard Nowak

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Since we're talking serial it's bits/sec. Parallel would be bytes/sec.

BTW: Baud and bps are the same for direct connections, not necessarily so
for modems.  With phase modulation and data compression data rates are going
up but the bandwidth of the telephone line limits the modulation to 1200 or
2400 baud.  2400 bps can be achieved at 600 baud, 14400 at 2400 baud.

Better telephone lines will raise the bar on these numbers of course.

Rich

At 03:55 PM 3/4/98 -0500, you wrote:
{Quote hidden}

>{Original Message removed}

1998\03\05@055056 by Keith Howell

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Alessandro Zummo wrote:
>
> The datasheet says:
>
> MAX232 (MAX202)     1.0 (0.1)
>
> Maybe the value in parenthesisi is referred to MAX202?

Yes, it is!

1998\03\05@061412 by Adrian Gothard

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At 21:24 04/03/98 +0200, you wrote:
>Il 04-Mar-98, Calvin scrisse:
>
>The datasheet says:
>
>MAX232 (MAX202)     1.0 (0.1)
>
>Maybe the value in parenthesisi is referred to MAX202?

Yes.

MAX232A can use 0.1u but not recommended due to startup problems.
......^
Regards

Adrian

WWW    WWW   Adrian Gothard
WWW WW WWW   White Horse Design
WWWWWWWWWW   0385-970009, 01189-628913/628914, 0976-387778 (obsolete)
WWWW  WWWW   spam_OUTwhdTakeThisOuTspamzetnet.co.uk
WWWW  WWWW   http://www.users.zetnet.co.uk/whd
---
Developers of GPS satellite-based tracking systems

1998\03\06@142606 by Craig Lee

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I've used them in general application at 160 kbps with the 1 uF caps.
Hint:
you can do this with a PC parallel port if you change the crystal from 3.xx
to 5.12 Mhz.  Just change your dividers.  This is pushing the hairy edge of
the PC's capability, but PIClisters are hackers anyways. No?

However,  depending on the batch, some of them have had communication
problems at this speed.

However, there is a type of MAX232 rated for higher than 160 kbps, so we
started buying that.  Check your supplier.


----------
> From: Brian Schousek <.....schousekKILLspamspam@spam@GEOCITIES.COM>
> To: PICLISTspamKILLspamMITVMA.MIT.EDU
> Subject: Re: Another MAX232 question
> Date: Wednesday, March 04, 1998 1:55 PM
>
>
>     Looking at the max23x datasheet I've got on my hard-drive(doc
19-4323;
> Rev 6; 3/96) page 1 shows the max 232 1u (.1u) capacitors and in the Data
> Rate (kbps) column it shows 120 (64) I would take this to mean that the
232
> can do 120 kbps w/1u and 64 kbps w/.1u.
>     The '232A is shown as achieving 200 kbps with .1u caps. I assume this
> means the 232A charge pump operates at a higher frequency.
>     To bring another thread into this, note that the acronym kbps is
> ambiguous. Could be kilobits, could be kilobytes. Only by looking further
> into the data sheet do we see kbits/sec spelled out. Therefore the 232 is
> capable of 64000/(8+1+1)->6400 baud with .1u caps.
>
> Brian
>
> {Original Message removed}

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