CMOS Vs TTL
The difference between the two Logic Styles are:
- TTL circuits utilize BJTs while CMOS circuits utilize FETs.
- CMOS allows a much higher density of logic functions in a single chip compared to TTL.
- TTL circuits consumes more power compared to CMOS circuits at rest.
- CMOS chips are a lot more susceptible to static discharge compared to TTL chips
- Propagation delay is more in CMOS compared to TTL
- Switching Speed is More for TTL compared to CMOS.
- CMOS devices are cheaper than TTL Devices.
- The Power Supply requirement for TTL is 3 to 15V, small fluctuations are tolerated.
- The Power Supply requirement for CMOS is 5V ±0.25V, it must be very smooth, a regulated supply.
- TTL Can handle only less frequency compared to CMOS.
Since TTL has very little parasitic capacitance, the time delay is very small, & TTL is faster.
MOSFETs, based on voltage operations, have much greater capacitances, the charging & discharging of which consumes time (Ref: RC time constant), hence CMOS is slower.
Comments
Post a Comment