Types of power consumption

There are basically two types of power consumption.

1. Dynamic

• Dynamic power is consumed during switching of transistors , And hence it depends on clock frequency and switching activity.  
• Dynamic power has two components. 
• Switching power
• This is the power that requires to charge and discharge capacitive load during logic transition from 1 to 0 and vice-versa.
• Internal power
• This is the power that consumed during transition . i.e. A point where both NMOS and PMOS are ON . Which is called as crowbar current.

2. Static

• Static power is transistor leakage current that flows when we apply power to a device.
• Main causes of static power consumption are as below.
• Reverse bias p-n junction leakage diode.
• sub-threshold leakage.
• Gate leakage.