I want to use CSNE151 current sensor in my control loop. Output of this device goes to the microprocessor then i have to decrease this output to 3 volt. i can't find suitable circuit model to apply it. In addition i want to know how can i adjust output of current sensor in my desired level?
Hello,
I'm not sure whether you already got that this a rather complex *bipolar, *current output sensor. Meaning:
1. Most likely there is no model (BTW: for which simulation program?) available.
2. I/V conversion is easily achieved by choosing the appropriate resistor value.
3. If measuring AC current you will not only have to I/V convert the output but also to level shift the resulting voltage as the µC is only capable to process positive voltages.
Is I haven't yet "played" with this specific device I'm not sure whether you will also have to correct load effects of the I/V resistor but that is easily evaluated with an evaluation circuit. But after a short look into the datasheet I'm quite sure that you will also have to cope with offset and temperature effects requiring some kind of cyclic (re-)calibration.
If you really have to 'model' the thing you might consider to either insert an appropriate sensing resistor at the "exit point" of your AC current - or a "current splitter" with 2 resistors at a ratio of 999:1 (the 1 including an eventual I/V resistor in parallel).
In simulations this is easily achieved as power loss is not really an issue :)
These 'models' will clearly lack the 'features' of offset and temperatur drift.
Hello Emad,
If you have this sensor with you, better you can build a small test circuit instead of modelling.
If we refer to the datasheet, it clearly states the output connections, recommended resistance and the output range.
Let's assume that you use 100 ohm to 300 ohm resistance at the output that will give you around 2500mV (100 ohm * 25mA) to 7500mV (300 ohm * 25mA). Then you simply add an op-amp buffer to avoid any overloading of the output of this sensor and then scale down the output voltage (of the op-amp) using a resistor voltage divider to a level more suitable to your ADC span.
If you do not have this particular sensor, then for the simulation purposes you can use any current source connected in series with this output resistor (of 100-300 ohms) and check your simulation model.
Please feel free if you have any further question.
Thanks and best wishes!
I did use a current sensor for my project last 8 years.. The most important thing you should allow the maximum voltage (converted) to half of your adc maximum input voltage.. Another thing to be considered is the level shifting... But some microcontroller can accept negative input such Vref+ = 3.3V and Vref- = -3.3V.. Selection of the microcontroller is another part in your project... All the best
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