EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: tip29 on March 21, 2018, 11:34:08 pm
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Hi all,
I just bought Siglent SDG1025 function generator mainly to generate pwm signal for DC/DC converter (I am trying to learn DC/DC converters).
I found its output @ 4Vpp square wave has 1V overshoot and ringing. I have attached a picture below. Is this acceptable?? Looks terrible to me.
Also, the falling edge has 20ns jitter. I read about the jitter problem on some posts and the solution was to use pulse function. But the ringing on pulse function is even worse.
I am just a hobbyist and this is my first function generator. I feel like I should have just gotten a used agilent.
Thanks.
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Are you using a normal scope probe? Have you tried connecting the BNC directly?
This is common because of the extra inductance of the probe's ground lead making a loop in the circuit and doesn't necessarily mean that it's actually being generated - it could be entirely an artifact of the way you are probing the signal.
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I had BNC to minigrabber cable from the SDG connected to the probe of the oscilloscope. The ringing diminished while probing BNC of the SDG directly.
I am stupid. :D
Thanks!
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As DaJMasta says, your probing/measurement techniques are the reason for this.
All Siglent AWG's are designed for 50 \$\Omega\$ impedance loads so to display the waveform accurately you must terminate into a 50 ohm load. Try a BNC cable and a BNC 50 ohm feed through.
Another trap for young players is the Load setting in the Utility menu. Hi-Z or 50 ohm selection ONLY adjusts the output voltage to match the intended load and as mentioned above the output impedance is always 50 ohm.
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I had BNC to minigrabber cable from the SDG connected to the probe of the oscilloscope. The ringing diminished while probing BNC of the SDG directly.
I am stupid. :D
Thanks!
It's been a while, but I've done it too. No worries :P