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s-ziel
Dec 21, 2020
In Welcome to the Forum
Hello, I have two additional questions. I understand that the J2111A Current Injector applies a small AC current to the output of a device when using the Voltage / Current measurement. The intent is to make a small signal measurement. What guidance is there when the load of the converter is well less than a 1A? Should I define "small signal perturbation" as "10% of the DC load"? If this is correct, then should I inject my own signal at 10mA/V when I have a DC load less than 250mA to maintain a small signal measurement? When using a DC block to isolate the DUT from the 50 ohm termination inside the Bode 100, it has been mentioned to watch out for inrush into the Bode 100 to prevent damage to the device. Is there any guidance on this, such as limiting the turn on ramp rate of the converter (such as perhaps 1V/ms)? Thanks!
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s-ziel
Dec 03, 2020
In Welcome to the Forum
I am taking an output impedance measurement using the 3-port (voltage / current) method. Here is my calibration test setup: I feel this is a very good test setup, and these are the shortest cables I can readily locate. Everything has the look and feel of "good working order" or is brand new. I used the J2102B as I assumed I would have low output impedance and in Steve Sandlers text, "Power Integrity", page 142 he discusses using the J2102B in this location for low impedance measurements. Here are the 1 ohm calibration results. Despite my best efforts I cannot remove the noise at the higher frequencies. I would like to verify that this is an expected result, or if something is incorrect in the test setup.
3 port, 1 ohm calibration results - is this right? content media
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s-ziel

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