Difference Between MOS and CMOS
MOS (Metal–Oxide–Semiconductor)
Refers to a single type of transistor, i.e., a MOSFET. It can be:
- NMOS (n-channel)
- PMOS (p-channel)
Used individually in circuits.
Key Points:
- Uses only one type of transistor at a time
- Simpler design
- Higher power consumption (especially NMOS logic)
- Faster in some basic configurations
CMOS (Complementary MOS)
A technology that uses both NMOS and PMOS together. “Complementary” means one turns ON while the other turns OFF.
Key Points:
- Uses both NMOS + PMOS transistors
- Very low power consumption
- Widely used in microprocessors, memory chips, and digital ICs
- More efficient and scalable
Main Differences
| Feature | MOS | CMOS |
|---|---|---|
| Transistors used | One type (NMOS or PMOS) | Both NMOS and PMOS |
| Power usage | Higher | Very low |
| Complexity | Simpler | More complex |
| Efficiency | Less efficient | Highly efficient |
| Usage | Basic circuits | Modern digital electronics |
Summary
- MOS = using just one worker
- CMOS = using a smart team where one works while the other rests → saves energy