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DRV421: Bandwidth and recommended core

Part Number: DRV421

Hi,

I am currently considering using this sensor in my thesis/project. I see there is a 2M hz bandwidth for the SHUNT SENSE AMPLIFIER in datasheet. So what is the bandwidth of this chip? Also, i can't find any core/coil suit for this chip on the market. Is there any suggestion  to design the mag core for this product?

Regards 

Desmond 

  • Hello Xiating Liu,

    Thank you for your interest in our DRV421.  The internal H-bridge driving the secondary should have the ability to keep up with a primary current even if it of a higher frequency.  Yet the internal differential op-amp will strongly attenuate any signal above 2MHz.  Therefore, we would say the part bandwidth is 2MHz.  However, your secondary could also influence the closed loop bandwidth.  For ease of use, I would encourage you to use the DRV421 System Parameter Calculator located on the Tools & Software tab of the DRV421 product page.  The magnetic core you will need to use depends on your operating conditions.  You most likely will need to custom fabricate the core you need.  On that note, many core vendors may not fabricate such a core for you if you do not plan on purchasing at least several thousand or millions of units. Despite this obstacle, one of my team members says it is possible to get a toroid and modify such that it is close to your specifications.  I imagine at your campus there is probably a machine shop for your mechanical engineering department.  I would see if they can help you with getting whatever toroid core you purchase cut to the specifications you need.