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TIDA-010048: TIDA-010048

Part Number: TIDA-010048
Other Parts Discussed in Thread: DAC8760, TIDA-01535

Hi Team,

We want to consider using TIDA-010048 for 4 -20 mA 2-wire transmitter.

  • 7-8 output channel – we want isolation from channel to channel
  • 2 input
  • We want isolation from Power supply
  • Power supply – 24V DC

We want to develop isolated from the power supply and isolated from channel to channel a 4 to 20mA output board module.

Will the TIDA-010048 support multiple isolated loops design solutions?

Kind Regards,

Neguse G.

  • Hello,

    I understand you want to develop a PLC/DCS module with 8 outputs, and 2 inputs. all are 4-20mA 2-wire channels.

    TIDA-010048 represents the 4 ch-ch isolated input module including 24V isolated power supply.

    for the analog output module ch/ch isolated, I do recommend using DAC8711 (if adaptive power management is required) or DAC8760 if you are going to use fixed supply.

    The power of those output channels is a bit tricky though.

    - power per channel depends on the maximum load, and power dissipation in the DAC. for maximum 24mA, and assumed 600 Ohm, we get 0.35W load power. considering the power dissipation in the DAC, this ends up with power requirement per channel in the range of 0.5W.

    from where do you plan to provide this power? back plane like in the TIDA-010048? then for 8 channels it is at 4W level after the isolation, so a power device capable of 5-6W is required. This is not actually common for AOUT modules. most of AOUT modules are powerd by 24V field supply. if this power needs to be isolated, then 24Vin isolated supply is needed per channel. this is a different stage than the one shown in the TIDA design. https://www.ti.com/tool/TIDA-01535 is showing an example of such power supply.

    Best Regards,

    Ahmed

  • Hello Ahmed,

    Thank you for getting back to me. Can you clarify and confirm the following...

    Each isolated 4-20mA output ports can either be powered externally, by an end user supplied voltage of 24 VDC at 600 W maximum, or internally, via the AC wall transformer.  This is selectable via internal jumper connections on the PCB.

    So, are you saying that we will need to have 8 separate design of TIDA-01535 POWER SUPPLY SOLUTION for 24Vin isolated supply per channel/output?

    Best Regards,

    Neguse

     

  • Hello Neguse,

    This is a design decision on your side.

    each channel is isolated from the backplane using a digital isolator, 

    How do you want to power those channels? and how their grounds could have different levels? if you want completely isolated ground, power sources for the DAC has to be isolated from the selected power source through a transformer, or isolated power module.

    if you are going to use the same power source for all channels, then they are not considered ch-ch isolated as they have galvanic connection through ground and supply nodes.

    Kind Regards,

    Ahmed