While effort was made to make the new devices drop-in compatible with the classic devices, there are differences when operated outside of the data sheet specifications.

One major difference is the Section 6.8 is inverted. The "B" and Ji3 Post-PCN#1 Single and Dual output can go high when both inputs are above VCM.

The Quad and post-PCN "B" devices have a different design, adding a clamp, to mimic the behavior of the classic die when both inputs are above VCM (output goes low).

Because the new designs are slightly faster with lower typical offset voltages, the comparator tends to be more sensitive to noise spikes, ringing and glitches that the older, slower classic design possibly ignored. Marginal system designs with excessive ground noise, very noisy input signals, noisy supplies or poor supply bypassing can now show false or multiple triggers. TI recommends proper supply bypassing (100nF minimum) directly between the supply pins. Input signals can be filtered to minimize high frequency noise and transients.

Due to the internal smaller device geometry and tighter junction spacing, the newer B devices tend to be slightly more sensitive to negative input voltages (voltages below the GND pin) and negative supply transients. Please see Section 6.9 for more information to protect against negative inputs.