Solution:

What is Logic levels?

• The voltages used to represent a 1 and a 0and Ideally, one voltage level represents a HIGH and another voltage level represents a LOW it's also known as Logic levels.

• There can be no overlap between the accepted range of HIGH levels and the accepted range of LOW levels.

Logic levels in digital circuits:

• In a practical digital circuit, however, a HIGH can be any voltage between a specified minimum value and a specified maximum value.

• Likewise, a LOW can be any voltage between a specified minimum and a specified maximum.

• Figure illustrates the general range of LOWs and HIGHs for a digital circuit.

• The variable VH(max) represents the maximum HIGH voltage value, and VH(min) represents the minimum HIGH voltage value.

• The maximum LOW voltage value is represented by VL(max),and the minimum LOW voltage value is represented by VL(min).

• The voltage values between VL(max) and VH(min) are unacceptable for proper operation.

• A voltage in the unacceptable range can appear as either a HIGH or a LOW to a given circuit.

• For example, the HIGH input values for a certain type of digital circuit technology called CMOS may range from 2 V to 3.3 V and the LOW input values may range from 0 V to 0.8 V. If a voltage of 2.5 V is applied, the circuit will accept it as a HIGH or binary 1.

• If a voltage of 0.5 V is applied, the circuit will accept it as a LOW or binary 0. For this type of circuit, voltages between 0.8 V and 2 V are unacceptable.