• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 65 subscribers
  • Views 138 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Current Control Solution

Jejomar Ildefonso
Genius 9490 points

Hi Team,

Asking your help to propose a current control device for our customer. The intention is to control the current coming from a multiplexer between 1µA -1000 mA using PWM switch or a switching MOSFET. They have 5 different current sources (1000mA, 100mA, 10 mA, 1mA and 1µA), so from this they need to control the current and provide a specified current (between 1 µA - 1000 mA)  in the output to carry out the measurement.

Thanks in advance!


Kind Regards,

Jejomar

  • 0
    TI__Guru 71526 points

    Hello Jejomar, 

      I am not certain as to what you are requesting.  Does the designer need a switch to select between the 5 current sources, or do they need a current source adjustable 1uA > 1A?  

    A block diagram with more detail would be very useful.

    Thanks,

    ~Leonard 

  • 0 in reply to LeonardEllis
    TI__Genius 9490 points

    Hi Leonard,

    Sorry for not being clear at my initial post. Either of your assumptions can be considered but they've mentioned that they'd prefer the adjustable current source approach. However I haven't seen a current reference which can provide up to 1A: www.ti.com/.../products.html

    If we have a much direct solution on the switch approach, we'd gladly look into it as well.

    Here's a simple block diagram:




    Thanks!


    Kind Regards,

    Jejomar


  • 0 in reply to Jejomar Ildefonso
    TI__Genius 10974 points

    Hi Jejomar,

    While our signal switches can be used for this type of application, none of our switches support 1A of current loading. We have some switches that can do 0.5A, but if 1A is a hard requirement, we do not have such a multiplexer device.

    Thanks!

    Bryan

  • 0 in reply to Jejomar Ildefonso
    TI__Guru 71526 points

    Hello Jejomar, 

      We are still not clear as to what is to be accomplished with this design.  If you already have an adjustable current source(s), then what would be accomplished by using them as an input to a PWM Controller? What are the voltage requirements? 

    Please provide more detail/definition.

    Thank you,

    ~Leonard  

  • 0 in reply to LeonardEllis
    TI__Genius 9490 points

    Hello Leonard and Brian,

    Thanks for your support. The current sources are not adjustable initially in the customer's design. They are searching for a solution to which they can provide 1µA - 1A in the output (adjustable using PWM) so that it can be used for measuring the voltage drop across diode and resistances with 4-wire measurement.

    The actual application is for measuring the voltage drop across PT-100, where the same 1µA - 1A current range will be provided and perform the voltage measurement across PT-100. The voltage can fluctuate up to 5V.


    Kind Regards,

    Jejomar