The OP said he needs a 1KHz sample rate. Those chips are about 50x to slow. Doing both high resolution and high bandwidth will be a hard problem.
On Wed, Sep 18, 2019 at 6:01 PM Nathan Hartman <hartman.nat...@gmail.com> wrote: > On Wed, Sep 18, 2019 at 9:38 AM Curtis Dutton <curtd...@gmail.com> wrote: > > > On Tue, Sep 17, 2019 at 6:17 PM Chris Albertson < > albertson.ch...@gmail.com > > > > > wrote: > > > > > If you want better than 16-bits and 1KHz then you also are going to > need > > a > > > very good quality analog signal conditioning and instrumentation > > amplifier. > > > The analog circuit between the A/D converts and the load cell really > > does > > > matter. You have to reject common-mode or the low bits will just > be > > > filled with 60Hz noise. And you can not simply use a "brick wall" > filter > > > or you will not get the desired bandwidth through. (If you are needing > > to > > > sample at 1K then you must care about 500Hz bandwidth. > > > > > > This matters a LOT more than which A/D chip you use > > > What you need is a Analog Front End (AFE) that is designed specifically for > a strain gauge. Usually that's a single IC (that probably requires some > passive components around it, which are specified in the datasheet) and if > you're not designing your own circuit board there are little circuit boards > ready made that you can get from Amazon that take the wires for a strain > gauge on one end and wires for power and SPI on the other end. There's a IC > called HX711 that's popular with Arduino enthusiasts. > > If you are building your own circuit board, the various AFE manufacturers > (Texas Instruments, Analog Devices, etc) tell you exactly how in their > datasheets, application notes, and reference designs. > > The difference between a AFE and A/D converter is that a AFE has the A/D > and also all the amplification and filtering etc built in to the chip, > whereas you'd have to build a pretty complex circuit board to do all of > that with discretes and op amps, and your results won't be as good as the > AFE chip. > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
