Current sensor

Nguyen Duc Hung

Other Parts Discussed in Thread: TIPD129

Hello,

For the moment, I'm looking for a current sensor to measure current in micro ample (uA). Does anyone tell me that TI have this type of sensor?

Thank you,

Hung

over 8 years ago

0 Rabab Itarsiwala over 8 years ago

TI__Expert 4595 points

Hi Nguyen,
We have a number of TI Precision Designs for sensing current. Visit www.ti.com/precisiondesigns and change App Function to Current Sensing.
Can you also provide details on common mode voltage (high-side or low side sensing) and power supply rails? I will transfer your post to Precision Analog Forum, where they will be able to assit further.

0 Nguyen Duc Hung over 8 years ago in reply to Rabab Itarsiwala

Prodigy 50 points

Hi Itarsiwala,

I want measure electrical current from 0 to 40mA with at least 1 uA resolution with at least 0.1% accuracy and require power supply of current

sensor from 2.7 to 5 V. I would be very grateful if somebody could tell me any current sensor to do this task.

Thanks

Hung,

0 Pete%20Semig over 8 years ago in reply to Nguyen Duc Hung

TI__Mastermind 25775 points

Hello Hung,

Please note that TI does not sell "current sensors". However, placing a precision resistor in series with the load current will generate a voltage proportional to the current. This voltage can be amplified and digitized by an ADC.

Here are some articles that may help in the design of your circuit:

www.eetimes.com/.../A-Current-Sensing-Tutorial-Part-1--Fundamentals

www.eetimes.com/.../A-Current-Sensing-Tutorial-Part-II--Devices

www.eetimes.com/.../A-Current-Sensing-Tutorial-Part-III--Accuracy

www.eetimes.com/.../A-Current-Sensing-Tutorial-Part-IV--Layout-and-Troubleshooting-Guidelines

As Rabab mentioned, there are a number of TI Precision Designs at www.ti.com/precisiondesigns that are designed for sensing current. I recommend evaluating TIPD129. The document describes the design in detail and gives all required equations. After reading the document you should be able to re-size the sense resistor for your current range. You can also download the design zip file and fabricate the PCB using the gerbers if you so desire.

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Current sensor