I am looking for a 5V capable CMOS D flip flop with a reset input. I found 74LVC1G74 and that would be OK. The only problem is (probably due to the “chip shortage”): it is difficult to find parts in any package other than the XSON8. I really prefer the TSSOP or at least the VSSOP
The first item of confusion is that Nexperia has FOUR different “XSON8” packages. These are mutually footprint incompatible because the lead spacing varies between 0.3, 0.35, and 0.5 mm. But let’s put that issue aside…
I thought I had figured out that the “1G” in a part number indicated the number of units in the IC package. So I searched for “2G74” thinking that it would be a dual. But NO !!! it is a single. And I am comparing the datasheets trying to figure out the difference between a 74LVC1G74 and a 74LVC2G74. Note that Nexperia is not the only company involved in this hijinks. TI seems to be in on it also. What am I missing? Are the 1G and 2G the same? Don’t get involved with this unless you know the answer or enjoy this sort of puzzle…
I would say that you should take the LVC1G and LVC2G as a complete chunk indicating the family. Since LVC1G appears to be derived from LVC, I think whoever wrote that it means single gate in the Wikipedia entry for the 7400 family was making a guess. (What does a single gate even mean for a device like a bus transceiver?) My counter-guess is that 1G and 2G mean first and second generation.
Thanks. It was completely my guess about 1G and 2G. There are other examples which support that hypothesis. Mainly I am trying to avoid a design error and trying to commiserate with comrades.
Actually my best guess on this now is that someone in the silicon business made an error in naming a part and then customers started buying it. So the die was cast…we have two different part numbers for the same part. Actually now I see that the 1G part is offered in four XSON8 packages (the 2G has only three) but SOT1089 appears to be the same as SOT1203. Note that they draw one rotated 90 degrees relative to the other so as to obfuscate matters.
Yikes!
Thank goodness I can have Chopin playing behind me as I shake my head about this…
I am using some LVC1G and LVC2G gates and also D flip flops but 1G79 or 1G80.
I have just checked - 2G79 means two D flip flops.
It is first time I see 2G doesn’t mean two units in the part. And I’m surprised.
For typical gates 8pin package means there are 2 of them inside. May be someone assumed that gates in 8 pin packages just are named 2G - the standard 14 or 16 pin IC divided by 2 ?
And later understood that if people search for 1 x 74 type D they search 1G74 and they should find that IC.
Why do the 74LVC2G74/1G74 have different part numbers but
same function? Both are single gate but the part number
indicates one has two gates included
Nexperia (then Philips/NXP) created the original device 74LVC1G74 (single D-type
flip-flop). A competitor released a functional equivalent later but named it the
74LVC2G74. The exact reason is unknown: either a simple mistake or an ingenious
method to create an apparent sole-source part number. To clear this confusion,
Nexperia now provides the same silicon under either part number, 74LVC1G74 and
74LVC2G74: one to match the original name and one to match the competition
name. There is no electrical difference between these two devices and they are in
fact the same silicon, package and top marking. We apoWhy do the 74LVC2G74/1G74 have different part numbers but
same function? Both are single gate but the part number
indicates one has two gates included
Nexperia (then Philips/NXP) created the original device 74LVC1G74 (single D-type
flip-flop). A competitor released a functional equivalent later but named it the
74LVC2G74. The exact reason is unknown: either a simple mistake or an ingenious
method to create an apparent sole-source part number. To clear this confusion,
Nexperia now provides the same silicon under either part number, 74LVC1G74 and
74LVC2G74: one to match the original name and one to match the competition
name. There is no electrical difference between these two devices and they are in
fact the same silicon, package and top marking. We apologize for any confusion this
caused but we didn’t start it!
Thanks a lot, @der.ule and @Piotr! It seems that I encountered a part number which is screwed up in a unique way. I note that the (simpler number) 74HC74 is a dual so at least for that reason the “2G” designator is not needed to indicate a dual. I still might use that dual if I cannot otherwise avoid the XSON08 package.
Son of a turkey! (I made up a new expression for USA Thanksgiving season.) Looks like you may be correct! I have opened up datasheets for 74LVC1G53 and 74LVC2G53. I wish there was a good way to dis-incentive the idea of obfuscation to achieve market share.
At least, the xxx74 and xxx53 individual units expose many I/O pins, and are not really candidates for a DUAL picogate, as this would defeat the whole purpose of the picogate concept (reduced pin count package).
But, yes, this is an insane situation ! Reading this post, I remember I’ve stumbled on the 2G74 mystery years ago.
I had to email TI to get clarification of some of their parts labelling for which spurious letters were used that never turned up in the keys, legends and codex. They didnt know and said they’d look into it.
Actually just got a reply. OMG they didnt even read it
"Hello John,
Regarding DAC8822 , please know this is just the generic part number (GPN) and there are many different orderable part numbers (OPN) under this GPN. In order to better assist, please provide the complete part number"
OMFG I literally linked the page with the 4 different codes on it! Id call that a fob-off. OK TI, guess Ill be getting my samples from Maxim then!