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The confusing picture

Found this, confusing picture on a popular ecommerce site, shows an extremely economical DC-DC (step-down) adjustable voltage converter (based on LM2596S), which apparently works for upto 2Amps of current, and usable on breadboards.

The part which is confusing is the DSO display, which is giving me the impression that this isn't DC, but dirty (triangular waveform) AC, possibly with the DC component bias. My initial thoughts were that this is a switching regulator (which it might very well be), but should the output stage waveform look like this ?

PS> If someone thinks that this is a shopping question, do advice on how to rephrase, because I am trying to make this a generic electronics fundamentals question.

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    \$\begingroup\$ From the text at upper-left, it looks like the 'scope is meant to show that the output ripple is 50 mV peak-peak. That's a fairly small ac signal, which might be acceptable in many digital applications, or which could be further filtered by the user. \$\endgroup\$
    – The Photon
    Nov 26, 2012 at 4:13
  • \$\begingroup\$ @ThePhoton, thanks. That's a perfectly acceptable answer to me, if put as such. \$\endgroup\$
    – bdutta74
    Nov 26, 2012 at 4:16

2 Answers 2

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From the text at upper-left, it looks like the 'scope is meant to show that the output ripple is 50 mV peak-peak. (I can't read the Chinese, I'm just guessing from the units).

That's a fairly small ac signal, which might be acceptable in many digital applications, or which could be further filtered by the user.

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50.4mV p-p if you zoom in on the display at 160.9KHz sounds right for a SMPS. 1% ripple at rated load of 2A is a good result.

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