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Part Number: DRV401


Dear Technical Support Team,


I have some question about DRV401.



The datasheet shows "GAIN FLATNESS vs FREQUENCY" below.

Could you tell me the reason why each "Normalized Gain" of M4645-X08 and X211 and X600 are different ?

Is it caused by the difference of eah functions?




How do I select the value of R3,R4,C4,C3 on Figure 8. Basic Connection Circuit?

Does they affect GAIN FLATNESS?



The datasheet doesn't show how to select the value of resister and capacitance.


R3 and R4, together with C3 and C4, form a network
that reduces the remaining probe oscillator ripple in
the output signal. The component values depend
on the sensor type and are tailored for best results.
This network is not required for normal operation.



Best Regards,


  • Hello  ttd,

    1)  The DRV401 drives each sensor and will have a different response as the impedance and response is not the same for varying sensors.  The impedance and how the fluxgate sensor saturates will change the response.

    2) The values are not shown as the operating frequency is dependent on the sensor.  Therefore you will need to filter out different frequencies depending on the response the DRV401 has with the fluxgate sensor.  There is more information regarding the oscillating frequency in the Magnetic Probe (Sensor) Interface section in the datasheet.   There is also a section below the schematic that the values of R3, R4 in combination with C3 and C4 be selected based on the oscillator ripple that can vary.


    Javier Contreras

    Best Regards,

    Javier Contreras, TI Sensing Products Applications Support

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