< b="" />CMOS (Complementary Metal-Oxide-Semiconductor)< />

CMOS, or Complementary Metal-Oxide-Semiconductor, is a type of logic family that dissipates the minimum power compared to other logic families such as DTL (Diode-Transistor Logic), TTL (Transistor-Transistor Logic), and ECL (Emitter-Coupled Logic). There are several reasons why CMOS is considered to be the most power-efficient logic family:

< b="" />1. Low Static Power Dissipation:< />
CMOS operates on the principle of using complementary pairs of MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), one P-channel and one N-channel, to form logic gates. When there is no switching activity, CMOS gates consume very little static power. This is because the MOSFETs in the CMOS gates are designed in such a way that they have a very high input impedance and do not draw any significant current when in a static state.

< b="" />2. Low Dynamic Power Dissipation:< />
Dynamic power dissipation occurs when the CMOS gates switch states. During this switching activity, there is a brief period of time when both the P-channel and N-channel transistors are conducting, leading to a brief short-circuit current path from the power supply to the ground. However, this short-circuit current is limited by the resistance of the MOSFETs, which is typically very high. As a result, the dynamic power dissipation in CMOS is significantly lower compared to other logic families.

< b="" />3. Symmetrical Rise and Fall Times:< />
CMOS gates have symmetrical rise and fall times, which means that the time required to transition from a logic low to a logic high state is the same as the time required to transition from a logic high to a logic low state. This symmetry allows for efficient power utilization and reduces the overall power dissipation in CMOS circuits.

< b="" />4. High Noise Margin:< />
CMOS gates have a high noise margin, which means they are less susceptible to noise and interference. This allows for better noise immunity and reduces the likelihood of erroneous switching, further contributing to the power efficiency of CMOS circuits.

In conclusion, CMOS logic family dissipates the minimum power compared to other logic families due to its low static and dynamic power dissipation, symmetrical rise and fall times, and high noise margin. These characteristics make CMOS an ideal choice for low-power applications, such as portable devices, where power consumption is a critical factor.