CD Datasheet, CD Single 8-channel Multiplexer/Demultiplexer Datasheet, buy CD Data sheet acquired from Harris Semiconductor .. CD MHz. VOS at Any Channel. MHz. Electrical Specifications Common Conditions Here: If. CDBMS, CDBMS and CDBMS analog multi- plexers/ demultiplexers are digitally controlled analog switches having low ON impedance and very.
|Published (Last):||3 December 2011|
|PDF File Size:||13.26 Mb|
|ePub File Size:||20.64 Mb|
|Price:||Free* [*Free Regsitration Required]|
The tolerance of the resistors won’t affect the stability of the current from your current source. I am interested in developing a generic 8-channel 4-wire PT interface for RaspberryPi. Futhermore, the is able to work with analog values; in the case of the Arduino, you are able to use the analog inputs with a voltage between V and route them to an Analog-In Pin on your Arduino.
The on resistance will vary over almost anything like supply voltage and temperature. Now could i multiplex the input voltages to constant current circuit? dahasheet
CD Datasheet(PDF) – National Semiconductor (TI)
Since it appears that the can support the 1mA what you could do to avoid Ron influencing the measurement is using separate multiplexers, one to multiplex the current feed it to a sensor the other to sense the voltage. Does this make sense?
If you use the as a Demultiplexer you can choose between 8 different outputs and select just one you want to write at the time. I have also included a resistance 2. In any case, CD voltage drop is excessive at much over 1mA.
If you really want to measure ‘top’ lead resistance for some reason other than break protection for which A0 suffices you can add another analog multiplexer and pick off the voltage at the ‘top’ of the RTD.
Datasheets search archive of electronic components datasheets
A multiplexer or demultiplexer enables you to expand the in-and outputs on your Arduino board. The current will always be 1 mA whatever value the resistor has. I will hand pick the resistors but what about temperature compensation? What is possible is to use a current source for each sensor and then only multiplexing the resulting voltage to the ADC input.
Finally i didnt go with the above but a modification using Bimpelrekkie ‘s suggesstions. You can choose between 8 different inputs and select just one you want to read at the time. Bimpelrekkie thanks for clarifying.
CD Datasheet Fairchild Semiconductor pdf data sheet FREE from
In this figure, the first wire of pt is supplied by 1mA current through a HC see footnote. I could order online but it would take weeks and cost a lot import duties to india. Bimpelrekkie One current source for each pt is a good idea, thanks. Needed accuracy must be better datasgeet 1degC and range from degC. Or reed relays could be another way? Here is the plan: Can i use transistors as switchs to route the 1ma instead of CD?
I checked with local supplier and they dont have this available. Sources for Electronic Parts.
Each of these pins have to be connected to one digital out pin on the Arduino. Sources for Electronic Parts. I already thank Bimpelrekkie and Spehro Pefhany for helping in such short period.
This is so because 1mA is passing through the 1st MUX. I guess i will have to go with the better versions of for now. As i have read in distributed posts here as well as in some papers eg. Instead i though i could make a differential measurement of voltage drop across the first two leads of the PT using A0 and A1 to get lead resistance.
However the high on resistance will still prevent you from reaching the required accuracy. The multiplexers would then be switched to the same input at the same time. See comment above with idea to replace 8 current sources datahseet one current source and one But i could never find how they practically implemented this or if its performance suffered and so on.
For current source, i have added 8 of these, each giving 1mA as per Bimpelrekkie. Post as a guest Name. Since i need to make a differential measurement between the first two leads of the pt while avoiding rds on of HC, i attached A0 of the ADC directly to the first wire through a schottky diode.
It may affect the actual current. Am i wrong or OK in this regard? If you have an ideal current source of 1 mA in series with a resistor, what will the current be? Related Hardware and Initiatives. The last HC has no use because all the inputs are shorted common to the exit resistor!
If you use the as a Multiplexer: Sign up or log in Sign up using Google.