+ Post New Thread
Results 1 to 4 of 4
  1. #1
    Advanced Member level 5
    Points: 34,858, Level: 45
    Achievements:
    7 years registered

    Join Date
    Sep 2008
    Location
    cambridge
    Posts
    7,245
    Helped
    524 / 524
    Points
    34,858
    Level
    45

    Resistor at input to high side current monitor IC

    Hi,
    Should resistor RP on page 1 of the HV7802 datasheet ideally be equal to the value of RA?

    HV7802 datasheet
    http://ww1.microchip.com/downloads/e...%20A062813.pdf

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 5
    Points: 13,290, Level: 27

    Join Date
    Aug 2015
    Location
    Melbourne
    Posts
    2,180
    Helped
    797 / 797
    Points
    13,290
    Level
    27

    Re: Resistor at input to high side current monitor IC

    "Transient Protection
    Add a protection resistor (RP) in series with the LOAD
    pin if VSENSE can exceed 5.0V in positive sense or 600mV
    in negative sense, whether in steady state or in transient
    conditions."

    from the data sheet Rp, p = protection ...


    1 members found this post helpful.

    •   AltAdvertisement

        
       

  3. #3
    Advanced Member level 5
    Points: 34,858, Level: 45
    Achievements:
    7 years registered

    Join Date
    Sep 2008
    Location
    cambridge
    Posts
    7,245
    Helped
    524 / 524
    Points
    34,858
    Level
    45

    Re: Resistor at input to high side current monitor IC

    Thanks yes,
    We have Rsense = 0R75, RA=1k and RB=3k3.

    I made RP=43k and readings (voltage on RB) were badly inaccurate.
    Now that we have RP=RA, the readings are good....

    ..the problem is, as you imply, we now dont have as good transient protection.

    We could make RA=RP=43k, but that makes the current really low and noise susceptibility may creep in.



    •   AltAdvertisement

        
       

  4. #4
    Super Moderator
    Points: 81,905, Level: 69
    Achievements:
    7 years registered
    Awards:
    Most Frequent Poster 3rd Helpful Member

    Join Date
    Apr 2014
    Posts
    16,630
    Helped
    3764 / 3764
    Points
    81,905
    Level
    69

    Re: Resistor at input to high side current monitor IC

    Hi,

    What V_sense do you expect, worst case?

    Klaus
    Please don´t contact me via PM, because there is no time to respond to them. No friend requests. Thank you.



--[[ ]]--