Voltage regulators are very common in electronic circuits. Note: Complete Technical Details can be found at the 7805 datasheet given at the end of this page. Junction Temperature maximum 125 degree Celsius.Internal Thermal Overload and Short circuit current limiting protection is available.It provides a constant +5V output voltage for a variable input voltage supply. The circuits for all these applications can be found at page 27/45 in the 78L05 datasheet given below.The 7805 Voltage Regulator IC is a commonly used voltage regulator that finds its application in most of the electronics projects. In that using a high current regulator like 7805 would be an ideal choice.Īpart from using it as a voltage regulator it can also be used as a current regulator, short-circuit protector, booster circuit and even a variable voltage regulator. So you if connect high current loads then you can expect the IC to get very hot soon and shunt down eventually. These regulators also have the ability to limit current and protect when the temperature exceeds beyond junction temperature. It’s not mandatory to use the exact value of capacitor but a value of 10uF for C1 and 1uF for C2 would be an ideal choice. These capacitors are used to filter any noise that’s coupled with the Input voltage. Because the maximum current that this IC could supply is only upto 100mA.Īlso note the Capacitors C1 and C2 are used at both the Input and output end. You use the 5V to power any small loads like LED which is rated for less than 100mA. In the circuit below a input voltage of 12V is regulated to 5V using the 78L05. It is very easy and straight forward to use this IC, just connect the input in to the input voltage which has to be regulated and the ground pin to system ground. The three terminals are Input, Output and ground as shown in the 78L05 pinout diagram. The 78L05 is a three terminal voltage regulator. So, if you are looking for a smaller package of voltage regulator that has small current rating in TO-92 package then this IC might be the right choice. This 0.35 Watts will be dissipated as heat.Īnother popular voltage regulator is 7805 which is bulkier in size but has high current rating of about 1A. For example if the input voltage is 12V and you are consuming 50mA, then (12-5) * (50*10^-3) = 0.35W. But, the IC suffers from heavy heat loss hence a Heat sink is recommended for projects that consume more current.
The output current of this IC can go up to 100mA. So our 7805 will provide a +5V output voltage. The name 78L05 signifies two meaning, “78” means that it is a positive voltage regulator and “05” means that it provides 5V as output. In our case the 78L05 IC is an iconic regulator IC that finds its application in most of the projects. They provide a constant output voltage for a varied input voltage.
Note: Complete Technical Details can be found at the 78L05 datasheet given at the end of this page.