Voltage regulators are very common in electronic circuits. They provide a constant output voltage for a varied input voltage. In our case the 7905 IC is an negative 5V regulator, meaning it provides -5V as output. The name 7905 signifies two meaning, “79” means that it is a negative voltage regulator and “05” means that it provides 5V as output. So our 7905 will provide a -5V output voltage.

The output current of this IC can go up to 1.5A, but the IC suffers from heavy heat loss hence a Heat sink is recommended for projects that consume more current. For example if the input voltage is 12V and you are consuming 1A, then (12-5) * 1 = 7W. This 7 Watts will be dissipated as heat.

7905 Regulator Features

• 5V Negative Voltage Regulator
• Output Voltage: -5V
• Output  Current: 1.5A
• Minimum Input Voltage is 7V
• Maximum Input Voltage is 25V
• Operating current(IQ) is 5mA
• Internal Thermal Overload and Short circuit current limiting protection is available.
• Junction Temperature maximum 125 degree Celsius
• Available in TO-220 and KTE package