[REQ] ACS758LCB-100B Current Sensor Sensitivity

[sohel]

Dear All

I am facing problem with ACS758LCB-100B Current Sensor , i cant get  C And D data Stable.

In Practical

A = 4.982V = VCC
B = 2.491V = VCC/2
C = 2.498V = Iout(V) (open circuit)
D = 0.007V = Difference

[solutions]

You need to at least put up a schematic. Your display & picture doesn't help us understand what you are doing, though you will get a lot of guesses

[sohel]

Thanks

have you any  code for this sensor? then i can figure out.

http://www.allegromicro.com/Products/Current-Sensor-ICs/Fifty-To-Two-Hundred-Amp-Integrated-Conductor-Sensor-ICs/ACS758.aspx

in data sheet page no 16 sayes 
Sensitivity (Sens). The change in device output in response to a
1 A change through the primary conductor.

so why i am going to sense 0.5A or 0.25A.

Sorry

[metal]

Why are our members always reluctant to show a schematic when they have a problem, don't worry, we will not steal your rocket-science project. Solutions asked for schematic, and I ask for your code for me and others to be able to help you!

[Ichan]

The request for schematic mean to know how do you read the output of the sensor, what adc? how many bits? etc.

The sensor is 100A bidirectional current sensor with sensing sensitivity in 2mV/A range, stray reading in 0.5A range is qualified "not bad" especially with breadboard construction.

Put more sugar on the table than many ants will come into it...

-ichan

[Gallymimu]

Yeah, without a schematic it will be hard to know if you are missing anything.  It's going to be hard to get the A/D working with any reasonable bandwidth on a breadbooard.  It looks like you might be using an A/D on an embedded processor.  Those are tough without careful power and ground routing.  Simple things like transitions on I/O pins to your LCD display while making A/D readings can have an impact.

Posted on: October 06, 2012, 03:56:42 15:56 - Automerged
some things to make sure you are doing if you do not plan to change your physical layout:

- only make A/D conversions while nothing else is happening (no recent I/O transitions). 
- Reduction of clockrate, or in sleep/idle mode for A/D conversion
- A/D oversampling
- digital filtering (simplest is modulo 2 avereraging, smoothing, or running average filter, 16 or 32 points would probably work)

on the hardware side
- make sure you have appropriate low pass filters right at the input to your A/D for anti-aliasing and noise reduction.
- are you using a separate voltage reference for A/D power and ref input?
- do you have RC or LC filter on A/D power and ref input?
- I assume you don't want to layout a PCB at this point but an appropriate multilayer PCB can make things very simple (you must follow best practices though)

[sohel]

thanks

Put more sugar on the table than many ants will come into it...

i have solved it. sensor vcc and microcontroller vcc should be same. sorry for my good English .

[solutions]

I hope that is ANALOG Vcc.....