Before revision: While TTL based design is similarly modular, it requires meticulous planning of a circuit's electrical load characteristics.Buffered models can accommodate higher electrical currents, but have a greater risk of introducing unwanted feedback .Understanding Buffered and Unbuffered CD4xxxB Series Device Characteristics.
After revision: While TTL ICs are similarly modular, these usually lack the symmetrical drive strength of CMOS and may therefore require more consideration of the loads applied on its outputs.Just like with TTL, buffered models can drive higher electrical current (mainly available for I/O-devices like octal latches and three-state drivers) but have a slightly higher risk of introducing ringing (transient oscillations) unless correctly damped or terminated .Understanding Buffered and Unbuffered CD4xxxB Series Device Characteristics.