DRV425: I need recommendation on MCU

Tim,

The DRV425 does consume max 10mA at 5V.  Are you planing to cycle the power to the DRV425?  This may be the only way you have low enough power for the DRV425 as it will already consume 50mW before you add the additional current required to drive the compensation coil.  The amount of compensation current will be dependent on the magnetic field you are measuring.  For example our transfer characteristic is 12.2mA/mT so if you were measuring 2mT there would be an additional current of 24.4mA. 

Also are you planning to have the MCU do the measurements with an integrated ADC?  What resolution are you attempting to get?  The bandwidth will decrease with increase in Rshunt?  How fast are you planning to get measurements and repeat it.

Hello Javier,
I need to detect a magnetic field intensity which is about 10 to 100 times large than the average earth surface magnetic field intensity in my area which is about 45uT.

Therefore, my target magnetic field intensity shall be in the range of 450uT to 4500uT, which is equal to 0.45mT to 4.5mT .

This target magnetic field only appears several times in 24 hours. I only need to record its sudden surge. There is no need to record its accurate value every bit of minute etc. So the MCU can sleep most of the time in one day and wake up if and on if it receives the sudden surge of the target magnetic field signal.

Does DRV425 fit my application purpose? Or could you recommend a better solution?


Yours faithfully.

Tim,

There are two issues with using the DRV425.  Its own power draw of the DRV425 by harvest power standards is large.  The other is the DRV425 has a maximum range of approximately 2mT.  We do have hall sensors to measure larger fields but the devices we currently have are designed to work with magnets and positioning so they are designed to drift the gain to match the magnet.  The other difference is that hall sensors technology in general is they cannot measure as accurate but are less expensive.  They also draw power and vary depending the version of the part.  The DRV5055 is bidirectional and the DRV5056 is unidirectional but they draw similar current as the DRV425 but they do not increase current as the magnetic field increase.

Hi Javier,
DRV5055 and DRV5056 sound good enough. My target is also a magnet which is big.

Are there any development kit, board or module to test the features of DRV5055 and DRV5056?


Yours faithfully.

Tim,

We have a few options and another will be available soon.

Please go to the product page of each device and click on tools and software to see all available options.  I have added links below for convience.

DRV5056_ToolsSoftware

DRV5055_ToolsSoftware