Don’t understand how Voltage Regulators work



  • Hello Everyone!

    I was wondering if anyone had a good explanation for how a Voltage Regulator works. I found this article but it’s a little to advanced for me. Can anyone explain it for a beginner? I don't understand some of the technical terms in the article etc…

    Thanks so much ! Any and all help would be greatly appreciated.



  • @rcolistete Even if that takes away the discussion from the initial question: voltage references are typically used as shunt regulators. The signal quality is fine, but the current consumption is constant at the maximum value for the set-up. Any current that is not used by the payload has to be absorbed by the voltage reference.



  • Another option is voltage reference integrated circuits :

    • allow some to 100 mA, depending on the model;
    • better line/load voltage regulation (output accuracy);
    • lower output voltage noise.

    Voltage reference are used as ADC references, etc. But can br used as supply to low power sensors or even low power microcontrollers.


  • Global Moderator

    Voltage regulators take in a range of voltages on V_in, and output a single set voltage on V_out. All relative to a common ground connection.

    Im not sure which exact voltage regulator you are looking for, but lets take for example the 7805, the input voltage range is 7-25V, and the output voltage is a fixed 5V. (Internally, they use several differential amplifiers current mirrors and an output stage to accomplish that). There will always be some voltage drop between the minimum input voltage and the fixed output voltage, in this case 2 V. As far as I know, it is not possible to step-up the voltage with a voltage regulator.

    If you need less voltage drop, you can use an LDO (low drop out) type, which have a lower minimum required voltage (generally 0.5V).

    For large voltage ranges or high current requirements, it is not recommended to use a voltage regulator, as they are not that efficient. For those scenarios, you can look at step down (or step up) converters as buck-boost supplies, but that is a whole different topic

    Hope I answered your question without making it sound complicated,
    Gijs



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