• AD5700/AD5700-1 RXD Activity After HART Carrier Off

    Referring to Figure 6, this plot is used to demonstrate “Carrier detect off” time (t5 in Table 3 of the datasheet). This is the time from carrier (i.e. HART signal) off to the CD signal falling edge. The time is 6 bit times max. The RXD signal behavior…

  • AD5700/AD5700-1 & Full Duplex Operation


    Can the AD5700/AD5700-1 support Full Duplex Operation?



    HART is, by nature, half duplex. It uses one channel (one pair of wires) for both directions. If one side is transmitting and…

  • RE: AD5700-1 with AD5420 communication with HART Modem

    Hi Ian,

    Proto rev1 has the AD5700-1 and AD5421 (loop power).  Proto rev2 is the AD5700-1 and AD5420 (non-loop power).  The failure occurs when communication with the HART Modem in both directions, where I see corrupted data.  Using the duplex pin on AD5700…

  • RE: AD5700-1 receive supply current in ordering guide table


    It is the total Vcc and IOVcc current consumed by the part when receiving or demodulating the HART signal.

    For AD5700-1, it includes the current consumption of the internal oscillator.



  • HART modem AD5700


    I'm trying to work with AD5700-1 according to CN-0382 circuit. I used internal oscillator and internal reference. When I connect 3.3V (feed from AD5421) to AD5700-1, I can't get any voltage or output on CLKOUT pin and voltage of REF pin is 1.7 V instead…

  • Ad5420 interfacing with AD5700-1

    • Hi

    I'm using AD5420 and AD5700-1 same as cn0270 in my design. 

    I'm getting hart out as a fsk over sine wave instead of fsk over DC line.

    I tried interfacing same hart circuit with ad5421 which is working fine. 

    But with ad5420 I'm getting below…

  • AD5700-1 Filter SEL


    I'm using AD5700-1 in my design.

    I'll be using external filter in my design. Whether it is allowed to provide FILTER SEL as high even when I'm using external filter and hart in is disconnected.


    Nidhi P Shetty

  • RE: AD5421 + AD5700-1 wrong loop current and lack of modulation

    Hi Denis,

    May I know what Loop voltage and RLoad are you operating on? 

    Also there is no modulated signal in the loop

    Do you have an oscilloscope capture of the loop current to check this? Or is there a HART slave/receiver on the…

  • RE: Difference between AD5700 and AD5700-1

    This question has been closed by the EZ team and is assumed answered.