User manual

PicoScope and oscilloscope primer22

5.13

Resolution enhancement

Resolution enhancement is a technique for increasing the effective vertical

resolution of the scope at the expense of high-frequency detail. Selecting resolution

enhancement does not change the scope's sampling rate or the number of samples

available.

For this technique to work, the signal must contain a very small amount of Gaussian

noise, but for many practical applications this is generally taken care of by the scope

itself and the noise inherent in normal signals.

The resolution enhancement feature uses a flat moving-average filter. This acts as a

low-pass filter with good step response characteristics and a very slow roll-off from

the pass-band to the stop-band.

Some side-effects will be observed when using resolution enhancement. These are

normal and can be counteracted by reducing the amount of enhancement used,

increasing the number of samples captured or changing the timebase. Trial and error

is usually the best way to find the optimum resolution enhancement for your

application. The side-effects include:

Widened and flattened impulses (spikes)

Vertical edges (such as those of square waves) turned into straight-line slopes

Inversion of the signal (sometimes making it look as if the trigger point is on the

wrong edge)

A flat line (when there are not enough samples in the waveform)

Procedure

Click the Channel Options button in the Channel Setup toolbar .

Use the Resolution Enhancement control in the Advanced Options menu to

select the effective number of bits, which can be equal to or greater than the

vertical resolution of your scope device.

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