About AD7366 Input Range

Hi,

My customer is trying to use the AD7366.
So I got a question.

#1 As a customer, he seems to want to input 0 to 12 V as an input range.

  In this case, should I set Vdd = + 12 V, Vss = -12 V, reference voltage = 3 V and RANGE 1, 0 both 1?

   

  If I want to select input ranges other than ± 10 V, ± 5 V, 0 V to 10 V, do I select "Do not program" in Table

  8 in the data sheet?
       Is there a proper use of the setting of ± 12 V and 0 V to 12 V?

Best Regards,

Yuya

  • 0
    •  Analog Employees 
    on Dec 21, 2017 6:05 PM

    Hi Yuya,

    For 0V to 12V input range, minimum Supply Voltage should be ± 12 V and the Reference Voltage should be 3V external source. And the Analog Input Range, RANGE1 and RANGE0 must set to 1 and 0, respectively. But please note that analog input signal should not exceed the supply rails by more than 300mV.

    Full-Scale Input Range is only available in preset values of  ±5 V, ±10 V and 0 to 10V when using the internal reference and values of ±6V, ±12 V and 0 to 12V when external reference of 3V is used.

    It is not advisable  to set the RANGE1 and RANGE0 to both 1 or to Do not program.

    Should you have any concerns feel free to ask

    Regards,

    Daryl

  • Hi, Daryl

    Thank you for the immediate reply.

    Does it mean that the analog signal does not exceed the power rail by 300 mV or more because you are conscious of the absolute maximum ratings?

    >> When using a 3 V external reference, values of ± 6 V, ± 12 V, 0 to 12 V can be used.

    Is the range setting of this not listed in the data sheet?
    As I understand from the answer, I recognize that it can be used with settings like the figure, is it right?

    Best Regards,

    Yuya

  • 0
    •  Analog Employees 
    on Dec 25, 2017 7:20 PM

    Hi Yuya

    You can refer also to Table 7 of  the datasheet. The maximum analog input signal depends on the selected reference voltage and Analog Input Range.

    I said last time that the analog input should not exceed the supply rails since it will damage the diodes used in ESD protection as shown in the figure below (figure 18 in datasheet). If the analog input exceeded the supply rails, the diode will be in forward-biased where any current greater than 10mA can cause damage.

    Regards,

    Daryl

  • Hi, Daryl

    Thank you for your answer.

    I understood the way of thinking.

    Moreover, I understood the reason why it should not exceed power supply voltage.

    Thank you very much.

    Wishing you a Happy and Healthy New Year!

    Best Regards,

    Yuya