Created on 2008-06-13 20:55:00
Applications Engineer Eric Schultheis examines how to test for glitches with a 2700 Series audio analyzer.
‘glich (noun) – derived from the German glitschig, or Yiddish glitsh, meaning ‘slippery’. (1) A short-lived fault in a system. (2) A false or spurious electronic signal caused by a brief, unwanted surge of electric power.
Although not a standard audio measurement, glitch detection can be beneficial to anyone designing an audio device or trouble shooting an audio system.
Examples might include checking a PC sound card to make sure audio response is flat as CPU usage varies, or measuring an amplifier where power up and/or down conditions may send an audible surge to connected loudspeakers.
Note: Some glitches are to be expected when state is changing, however, the degree of what is acceptable can certainly be measured and given a limit.
In this example we’ll set up a test to detect a glitch using a SYS-2722 audio analyzer. You can also perform this test with an ATS-2.
Setting up the test
In the Settling Panel, change the Analog Analyzer THD+N Amplitude Settling Algorithm to None and its delay to 0.00 sec. This will post readings to the graph instantly (without waiting for settled readings).
Finally, click the Sweep Start button in the tool bar or on the Sweep Panel. While the sweep is running (60 seconds duration) apply the condition to your DUT under which you expect the glitch to occur.
In this example I toggled the Analog Generator off and on at the 30 second mark and the resulting glitch is visible on the graph.
Graph of detected glitch.
- You may download this example test file “glitch_detection.at27” at the link below.
AP2700 test file to accompany the knowledge base article on Glitch Detection.