Hall sensor output voltage not zero when sensed current is zero?

[treez]

thanks, as you say , it looks like the 0.1xvcc is in every reading...not just those less than 1.25A.

(We just want to use it to sense current for the Vicor PRM48' module in remote sense mode.)

 

[D.A.(Tony)Stewart]

Isn't remote sense mode for voltage.?

 

[treez]

yes but in remote sense mode the current monitoring needs to be done externally from the module...just a nuance of it

 

[D.A.(Tony)Stewart]

Not sure I would trust the stability of a digitally compensated Hall Current Sensor in an analog negative feedback loop.
Is it Monotonic? If not gauranteed then spurious instabilities may arise.

 

[treez]

thanks, but it has a bandwidth of 80khz

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Not sure I would trust the stability of a digitally compensated Hall Current Sensor in an analog negative feedback loop.
Is it Monotonic? If not gauranteed then spurious instabilities may arise.

There have been a large number of posts on edaboard regarding current regulation into LEDs and battery chargers using a hall sensor as the current sense element….there have been no such problems flagged up before.

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-nowhere in the ACS724 datasheet is the word monotonic actually mentioned.

 

[treez]

d123 thanks for your great current monitor chip recomendations, sorry to have lost them , you kindly recomended INA282 which is ace, but also the analog devices one which i cannot remember the part number of?...sorry to ask.

 

[d123]

Hi treez,

Sorry, I can't even seem to find the reference to it in the actual thread where it was first mentioned...

 

[D.A.(Tony)Stewart]

thanks, but it has a bandwidth of 80khz

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There have been a large number of posts on edaboard regarding current regulation into LEDs and battery chargers using a hall sensor as the current sense element….there have been no such problems flagged up before.

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-nowhere in the ACS724 datasheet is the word monotonic actually mentioned.

Anyone who has tested an ADC for Monotonic behavior will understand what I'm saying.

When you have high resolution and non-linear correction and temperature correction covering a wide range, you can have Monotonic errors. They may be small but they will result in a momentary positive feedback path during that interval that increase the noise level or cause other random glitches.

If they do not gaurantee monotonicity, then I Can gaurantee you it isn't, but it may be small enough to not matter. If used for PFM feedback control , they may say dither control is good for lower EMI "Spurs" because they added random jitter.

If an ADC/ DAC is guarantee Monotonic within 1/2 bit, it will say so. I have found many that weren't. (Burr Brown Mil-std 883 ADC, my LCD TV using a 2Mpixel x3 image gradient test pattern on 1080p, others..

**broken link removed**

NEver assume,. Ask the OEM tech support.