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Very few people use analog signal processing techniques these days. It used to be common up until about 10-15 years ago, but then DSP's came along. Now, you t
by swamp40 12y ago
Very few people use analog signal processing techniques these days.
It used to be common up until about 10-15 years ago, but then DSP's came along.
Now, you take a signal, buffer it by the minimuum amount necessary to get it into the DSP, and call it a day.
The best case is, you don't touch the signal at all, because any caps, filters, op amps can all distort the original signal.
You can do it all digitally, and it's much easier to modify on the fly if your technique isn't working well.
Boards and boards full of touchy analog electronics have been replaced by a single DSP.
And not many people are looking back.
- agoetz 12y agoSignal conditioning is still an important part of EE design. Not all signals are TTL level and unipolar. For example, this appnote[0] uses a Delta-Sigma converter to digitize a load cell, with the ability to "detect one sheet of copier paper dropped on a stack of 20 reams". In order to do this, it relies on an intrumentation amplifier and custom correlated-double sampling to get a measurement accurate to 200,000 counts. And even if your input signal can be directly input to your ADC, you'll still need an analog anti-aliasing filter. Signal conditioning is an important part of signal processing that has to happen in the analog domain. [0] http://cds.linear.com/docs/en/application-note/an96fa.pdf http://cds.linear.com/docs/en/application-note/an96fa.pdf
- swamp40 12y agoI agree that we haven't yet eliminated all analog conditioning. Your example however, doesn't really bolster your point. Delta-Sigma modulation is a digital signal processing technique. That particular chip is also using a digital FIR filters to reduce noise.
- pkaye 12y agoYou still need analog engineers for SoC chip design including voltage regulators and detectors, PLL and clock generation, IO pads.