I can't understand about voltage regulator and reference....

Discussion in 'Power Electronics' started by Junho Kim, Jul 18, 2016.

  1. Junho Kim

    Thread Starter New Member

    Jul 18, 2016
    Hi! I'm a student and studying designing circuit.
    I can't not understand about regulator and reference.... what is difference between them?
    I think there are two kinds of Voltage regulator, linear and switching regulator.
    Linear regulator includes shunt and series.
    I wonder when i have to use shunt(ex TL431) or series regulator(ex LM7805) and their pros and cons.
    When can i use regulator or reference? I'm so confusing....
    I'm sorry about my poor English but I believe you can understand what I mean!
  2. Papabravo


    Feb 24, 2006
    A reference is just a stable fixed value. It is primarily used in circuits where a comparison between two voltages is required. A reference cannot supply large amounts of current. A few milliamps would be about the maximum output current.

    A regulator incorporates a reference to determine which way the voltage output must be adjusted to maintain a constant output voltage when the load changes. Regulators supply 100's of milliamps to tens of Amperes of output current.
    Junho Kim likes this.
  3. Junho Kim

    Thread Starter New Member

    Jul 18, 2016
    Thank you for your reply. I have some questions.
    I'm making a charger circuit for smartphone. I used TL431. Is it a regulator or reference?
    I think charger circuit needs to limit current. Then do i have to use reference not regulator like 7805?
    If i need large current, i have to use regulator. Is it right?

    I looked at TL431 datasheet but i couldn't find how to operate it.....
    Last edited: Jul 19, 2016
  4. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    Didn't you see all the "System Examples" in the datasheet?
  5. BobTPH

    Senior Member

    Jun 5, 2013
    If you are talking about making a USB plug type charger that cell phones universally use now, you do not control the current. You supply a constant 5V. The circuitry to control the current while charging the battery is inside the phone. If you leave the D+ and D- pins alone, you phone will draw a max of 500mA and you must be able to supply that.