AD7693 damage

AD7693 is widely used in our data acquisition system.  Over the years, we have seen damaged AD7693 time to time. Most of the cases, the current draw goes up and the chip gets really hot. Recently, a AD7693 chip still works but spins out garbage data.  Does anybody have a similar experience?  Please do share. Thanks

  • 0
    •  Analog Employees 
    on Oct 25, 2018 11:56 AM

    Hi,

    It is very uncommon for an ADC to get hot. One reason of drawing a lot of current is operating on the maximum rating. It should consider that the inputs (both analog and digital) are connected to its respective voltage supply through a diode (ESD).

    For me to help you in your concern, can I have your schematic and the input voltage range. If you can provide your application, the better.

    Regards,

    Daryl 

  • Daryl, Thanks for the reply. 

    I have to ask permission before I can share the schematics.  It's a typical multiplexed data acquisition system.  The analog input is 0-5V and the digital side is 3.3V power rail. 

    The analog front end is from about 8 different sensors, which have been conditioned to 0-5V output. The analog signals are multiplexed by two ADG658YRU, follows by ADA4941 single-end to full differential driver, then to the AD7693BRMZ. The digital controller is Xlinix XCR3064XL. Since all the digital signal lines to the ADC are internal to the circuit board, so there is no extra ESD protection. 

    I might be able to send you a schematic later. 

    Thanks again.

  • Hello, Daryl 

    I am not able to post the schematics in the forum. Is it possible for me to email you the schematic for a review? Thanks