Reply-To: "Martin Riddle"
From: "Martin Riddle"
Subject: Re: Related question
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
Date: Tue, 21 Jan 2003 23:31:27 GMT
NNTP-Posting-Date: Tue, 21 Jan 2003 15:31:27 PST
Organization: EarthLink Inc. -- http://www.EarthLink.net
Cable marked for 'Data' usage typically has the lowest capacitance/foot. Other control cables may
not list the capacitance.
Get a 2 twisted/pair cable and run SCL/VDD and SDA/VCC, this will minimize the capacitance.
You could even do twisted Ribbon cable, common in some micro emulators.
www.alphwire.com lists their Data cable (alpha byte) as 8pf/f and 15pf/f to shield.
"Mark Jones" wrote in message
> Looking through this datasheet, I have a similar question about serial bus
> speeds (snippet below.) I'm working on a deisgn that uses the SHT75 digital
> 2-wire non-I2C sensor from www.sensiron.com, but it reccomends lead length
> be kept as short as possible (6 inches.) In my application I need the sensor
> to be around 18 feet away from the uC - imposing significant parallel
> I understand the serial frequency will have to be lowered and that's ok.
> Question is, if using four-wire cabling, (sclk & data, vcc & vdd), are
> there any particular types or grades that would be of low enough capacitance
> to be suitable? Or is this just an impossible request?