Data sheet acquired from Harris Semiconductor. SCHSD. CAUTION: The CDB, CDB, and CDB analog multiplexers are digitally-controlled . Product data sheet. Rev. 12 — 25 March 4 of Nexperia. HEFB. 8- channel analog multiplexer/demultiplexer. Fig 5. Logic diagram. An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in . Product Folder Links: CDB CDB CDB.
|Published (Last):||12 November 2005|
|PDF File Size:||18.47 Mb|
|ePub File Size:||14.26 Mb|
|Price:||Free* [*Free Regsitration Required]|
I saw a comment on the ‘arduino’ board which said that “the for loop repeatedly cycles count from 0 to 7, so [selector pins] will average 2.
Sign up using Facebook. Sign up using Email and Password. If I start reading random ports between 0 and 7it reads correctly for about 10 seconds, then suddenly starts reading zero.
(PDF) CDB Datasheet PDF Download – CMOS Analog Multiplexers / Demultiplexers
I’d try using a different board. Still, I was hoping for a method that wouldn’t tamper with the input signal in any way: I’m a bit lost to what the problem could be. But it changes nothing.
Home Questions Tags Users Unanswered. I’m using a breadboard of questionable quality. At the very least, connect a pullup resistor of about 10K between IN and the 5V power source. I’ve tried removing the pull-down resistor. Datasheet simulate this circuit — Schematic created using CircuitLab I’ve connected the input to 5V for testing stability of the reading.
A 10K resistor works well in most cases. Email Required, but never shown. What is the signal source that you’re reading? That is what seems to be the source of your problems. Is there a better alternative? I’ve experimented with various delay times, and 30ms seemed to improve things a lot when reading sequantially 0, 1, 2, I did try to add a 10k resistor in series with the input, but it changed the output.
Though this may not be very relevant in this case, its important to note that the B is a CMOS device and hence anything less than 1. This means that this chip will not work with 3.
Datasheets search archive of electronic components datasheets
I’ve also tried adding a 1uF capacitor. But this happens even with 1k resistor on Input 4. I’m using digitalWrite on three pins to select the input port, and then waiting delay for 30ms before doing an analogRead on A0. The Arduino has about 10Mohm resistance on the input side, so it shouldn’t make a difference, but the max reading was about instead of The IC has internal protection circuits.
The value then starts reading randomly. You show that you’ve got your “Signal” leads connected to the select inputs.
If I read only port 4 for 30 seconds, it starts to read correctly and stable. I’ve connected the input to 5V for testing stability of the reading. I haven’t seen the block diagram for the chip but it seems that you may be shorting something internally inside the chip which is why the input drops to 0V after a short time.
I’ve tried changing the pull-down resistor. Look at page 4 of this guide.
Wouldn’t the digital pins be able to sink fast enough that the IC would mux correctly? I imagine it could be something with capacitance on the ports, but I have the impression that the multiplexer is actually supposed to support very fast switching?
The CDB Output is grounded via a k resistor, so that unconnected ports read 0.