On Monday 29 Sep 2003 6:48 pm, you wrote: > > I must confess I had not read this far in the data sheet. However, mine > > only shows an example of using the control pin as an input via an 80K > > resistor and makes no reference as to how this might alter the > > hysteresis. Can you give me a URL reference to your data sheet? > > This is the reference. Refer to figure 2 (internal schematic). Also the > the text: "The response node may also be used as the receiver input as > long as the designer realizes that he may not drive this node with a low > impedance source to a voltage greater than one diode above ground or less > than one diode below ground. This feature is demonstrated in Figure 13 > where two receivers are slaved to the same line that must still meet the > EIA232D impedance requirement." > > This means that you can use the 'response node' as input using a resistor > different from the original one (3k8). You can also use the normal input > with an additional series resistor, with the same effect. With Rext = 3k8 > on the normal input the hysteresis should double (still asymmetrically). > > Peter Thanks for taking the time to explain that. Ian -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads