Hi Team,
A customer is looking for an equivalent device to National Semiconductor's MM70C97J/883. Upon checking our list of tri-state hex buffers, I found SN54HC367. Can you please confirm if it can be use as replacement for MM70C97J/883?
Regards,
Danilo
Hey Danilo,
Both datasheets show the functionality and pinout clearly - they just show it differently.
Since these are both logic devices, the best way to compare functionality is through the function table & pinout.
You haven't linked me to a datasheet for MM70C97J/883, so I'm just going to assume I have found the right one (from National Semiconductor, 1988):
Compared to the SN54HC367:
Comparing the two, I see that VCC and GND are on pins 16 and 8, respectively, for each device - so that's a match.
The MM70C97 has a very confusing diagram to show that it has buffers with 3-state outputs and inverted output enable pins (DIS2 and DIS4). These directly align with the OE\ pin positions for the SN74HC367, which have the same function to disable the outputs. 1OE\ controls all of the '1' buffers, and 2OE\ controls the two '2' buffers.
Checking the pins of each buffer, you can see that pins, 2, 4, 6, and 10 are inputs on both devices for the bank of 4 buffers.
You can also see that pins 3, 5, 7, and 9 are the outputs for both devices. The orientation of all buffers for the bank of 4 align.
You can then check the pins of each buffer for the second bank, inputs on 14, 12 and outputs on 13, 11 -- which aligns with the SN74HC373 also.
The TI datasheet indicates that the outputs are placed into the Hi-Z state when disabled, and disabling them requires a HIGH input on the OE pin. The NS datasheet shows the same - a HIGH on the DIS input will set the appropriate set of outputs to the Hi-Z state.
So - check, we've verified that the MM70C97 and the SN74HC367 are _functionally_ equivalent. Next up is to verify if they are _electrically_ equivalent.
Just glancing quickly over the abs max ratings, we can see very quickly that there's at least one big difference in these two parts -- the MM70C97 is designed to operate up to 18V, while the SN74HC367 is designed to operate to only 7V (abs max).
Looking further into the datasheet we can see that there are many differences in performance -- the SN74HC367 is rated for 6mA output at 4.5V, while the MM70C97 is only rated to 1.6mA at 4.5V. Looking further we can see a lot of differences.
So - could these two work in the same socket? Perhaps. For 3.3V to 5V and applications where the timing isn't important (HC will have about 10ns of delay, MM70C97 will have more like 100ns)
If the CD54HC367 or SN54HC367 (they are interchangable) will work, I'd recommend using it - it's a much newer device and will provide better performance - and is much more popular.
**
We only have one logic family that supports 18V operation, so I took a quick look and found the CD4503B-MIL, which seems to be a direct replacement. It even says "Pin compatible with industry types MM80C97..." in the first page of the datasheet.
