+ Post New Thread
Results 1 to 6 of 6
  1. #1
    Member level 1
    Points: 1,687, Level: 9

    Join Date
    Sep 2004
    Posts
    40
    Helped
    1 / 1
    Points
    1,687
    Level
    9

    What is the Line and Load regulation in LDO design ?

    What is Line and Load regulation ? why do we need to take care on it on circuit design ?

    For LDO design, How do we measure them ?

    I have read a paper on LDO design such that it is "stable on any Cap. value". is it possible to do so ?

    THANKS

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 4
    Points: 11,124, Level: 25
    Achievements:
    7 years registered
    safwatonline's Avatar
    Join Date
    Nov 2005
    Location
    EGYPT
    Posts
    1,347
    Helped
    220 / 220
    Points
    11,124
    Level
    25

    LDO design

    line regulation the the variation of the output voltage with the input (supply)
    load regulation is the vriation of the output voltage with the load current
    causeu are designing a regulator so u need a stable (fixed) output regardless of the supply and load



    •   AltAdvertisement

        
       

  3. #3
    Member level 1
    Points: 1,687, Level: 9

    Join Date
    Sep 2004
    Posts
    40
    Helped
    1 / 1
    Points
    1,687
    Level
    9

    Re: LDO design

    Thz reply ~~

    But...how about the measure....how do i measure the line and load regulation in LDO ?



    •   AltAdvertisement

        
       

  4. #4
    Full Member level 2
    Points: 2,184, Level: 10
    scottieman's Avatar
    Join Date
    Aug 2005
    Location
    On Top of Silicon
    Posts
    136
    Helped
    12 / 12
    Points
    2,184
    Level
    10

    Re: LDO design

    Quote Originally Posted by ee_cchac
    Thz reply ~~

    But...how about the measure....how do i measure the line and load regulation in LDO ?
    For line regulation, simply change the supply voltage loctaed in your lab. In the mean time, you should make sure the load current is maintained at the level you wanted.

    For load regulation, simply use a variable resistor to adjust the output current. Of course, again, you need to make sure the input voltage is the same for all cases of load current.

    Hope it helps
    Scottie



  5. #5
    Member level 3
    Points: 1,981, Level: 10
    Achievements:
    7 years registered

    Join Date
    Feb 2007
    Posts
    55
    Helped
    5 / 5
    Points
    1,981
    Level
    10

    Re: LDO design

    In other words:

    For load regulation:

    Introduce a current square form on the output (with modest frequency) from zero to Imax and look at the output voltage. The maximum voltage variation will give the load regulation.

    For line regulation:

    Change the voltage source (Vdd or Vin or whatever you call the supply voltage) from Vmin (Vout + Vdrop-out) to a specifical value you like, then measure your output voltage. The line regulation will be:

    (delta Vout)/(delta Vin)

    These are pretty important characteristics to take into account, specially load regulation because normally you won't have a stable power sinker on a battery supply environment.



    •   AltAdvertisement

        
       

  6. #6
    Full Member level 2
    Points: 2,312, Level: 11

    Join Date
    Sep 2006
    Posts
    125
    Helped
    15 / 15
    Points
    2,312
    Level
    11

    Re: LDO design

    Line/Load regulation are the power supply and load variation affect on LDO.



--[[ ]]--