AD5420 gain and offset compensation

Hi all,

I use an AD5420 to produce a precise 0-20mA output current.

Is it preferrable to compensate the offset and gain errors by firmware or there is some internal compensation circuitry in the AD5420 to do this ?

In the AD420 the compensation can be done using two external dedicated pins.

Thanks in advance for any suggestion

  • 0
    •  Analog Employees 
    on Feb 16, 2012 1:29 PM

    Hi,

    For improved offset and gain error specification I'd recommend using an External RSET.

    Offset Error is +/-0.1%FSR max, and Gain Error of +/-0.08%FSR max.   

    There is no specific Offset and Gain registers on the AD5420 or a similar trimmable

    offset like the AD420. 

    The AD5755 offers a programmable Gain / Offset option in the internal calibration settings. 

    Regards,

    Michael

  • Hi,

    I can't find descriptions of how to program Gain / Offset in the datasheet. Only thing I can find about internal calibration registers in the datasheet is in 'power-on state' section, which does not tell how to program gain / offset.

    Could anybody advice me where I can find a documentation in which programming gain/offset is explained in detail?

    Thanks,

    Tatsuya Minami

  • 0
    •  Analog Employees 
    on Oct 30, 2012 11:00 AM

    Hi,

    The AD5755 offsets gain and offset registers on the part.  (M + C registers).

    These are detailed on page 34 of the AD5755 datasheet. 

    The AD5420 does not have internal gain/offset registers. 

    Regards,

    Michael (PDA Applications)

  • Oops. I'm sorry. I missed "AD5755" part and thanks for the clarification.