Voltage Regulator Internal Circuit

Thread Starter

Engr

Joined Mar 17, 2010
114
Hi Guys,

Can someone tell me what is inside a Voltage Regulator IC. I am trying to understand how a voltage regulator IC does the voltage regulation that is why I need to know what is inside a Voltage Regulator IC.

Thanks and Best Regards,
Engr
 

hgmjr

Joined Jan 28, 2005
9,027
Have you a particular voltage regulator in mind? I would suggest consulting the manufacturer's datasheet. They are usually pretty good at providing an equivalent internal circuit schematic.

hgmjr
 

Thread Starter

Engr

Joined Mar 17, 2010
114
Have you a particular voltage regulator in mind? I would suggest consulting the manufacturer's datasheet. They are usually pretty good at providing an equivalent internal circuit schematic.

hgmjr
What I have in mind are the 78XX Series and 79XX Series Voltage Regulator. Your right, they are really good at it but I doubt if they are going to give an equivalent circuit of their own products.. But still, I am going to try it..
 

Audioguru

Joined Dec 20, 2007
11,248
It has a voltage reference, a high gain error amplifier and a series pass transistor. It has a current limiting circuit. It also has a circuit that detects that it is too hot and shuts it down until it has cooled.

If the output voltage is too low then the error amplifier senses that the output is lower than the reference voltage so it turns on the series pass transistor harder to raise the output voltage.
If the output voltage is too high then the error amplifier senses that the output is higher than the reference voltage so it turns on the series pass transistor less or turns it off to reduce the output voltage.
 
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