## Sunday, September 19, 2021

5V Regulator design tutorial - How it works, how to design PCB altium

Voltage regulator. Learn how to make a 5V regulator using capacitors, LM7805 regulator and Schottky diode, learn how the circuit works and also how to build your own PCB printed circuit board, how to order a PCB and how to solder the boards electronic components together.

Regulator Types
Fundamentally there are two types of voltage regulators:  linear and switching.  The names come from how they operate and how they achieve voltage regulation.  Linear regulators tend to be a little cheaper to implement, but they aren’t as efficient as their more complex switching variants.

There are also some “cheap and dirty” methods that some designs use.  Below is a brief description and example of each.

Linear
A simple way to think of a linear regulator is to think of it as an active series resistor.  It will vary its effective resistance so that the output voltage remains the same.  The upside to such a design is that it is cheap, simple to implement, and provides a relatively clean output.  The downside is that the regulator dissipates a relatively large amount of power.

If you consider a linear regulator as a series resistor, you can understand how it dissipates power.  The voltage drop of the regulator is like that of a resistor:  the difference between the input side and output side.  So if a nominal 9V goes in and a nominal 5V comes out, there is a nominal 4V drop.  Using the equation Power = Current * Voltage you can see that even 100mA of current causes 400mW of heat dissipation.  That is 400mW of power just lost!

5V Regulator design tutorial - How it works, how to design PCB altium

Voltage regulator. Learn how to make a 5V regulator using capacitors, LM7805 regulator and Schottky diode, learn how the circuit works and also how to build your own PCB printed circuit board, how to order a PCB and how to solder the boards electronic components together.

Regulator Types
Fundamentally there are two types of voltage regulators:  linear and switching.  The names come from how they operate and how they achieve voltage regulation.  Linear regulators tend to be a little cheaper to implement, but they aren’t as efficient as their more complex switching variants.

There are also some “cheap and dirty” methods that some designs use.  Below is a brief description and example of each.

Linear
A simple way to think of a linear regulator is to think of it as an active series resistor.  It will vary its effective resistance so that the output voltage remains the same.  The upside to such a design is that it is cheap, simple to implement, and provides a relatively clean output.  The downside is that the regulator dissipates a relatively large amount of power.

If you consider a linear regulator as a series resistor, you can understand how it dissipates power.  The voltage drop of the regulator is like that of a resistor:  the difference between the input side and output side.  So if a nominal 9V goes in and a nominal 5V comes out, there is a nominal 4V drop.  Using the equation Power = Current * Voltage you can see that even 100mA of current causes 400mW of heat dissipation.  That is 400mW of power just lost!