SN74LVC373A: Logic forum

Richard Staebler

Prodigy 50 points

Part Number: SN74LVC373A
Other Parts Discussed in Thread: SN74LVC16373A, , SN74AUC16373

Hello,

why are the max switching characteristics are so different between
SN74LVC373A and SN74LVC16373A at 1,8V ?

SN74LVC373A: 8-Bit

SN74LVC16373A: 16-Bit

Overview

VCC=1,8V	SN74LVC373A 8-Bit	SN74LVC16373A 16-Bit
tpd max D > Q	19,1ns	6,4ns
tpd max LE > Q	22,8ns	7,1ns
ten max nOE > Q	20 ns	6,7ns
tdis max nOE > Q	19,3ns	8,4ns

Best regards

R. Stäbler

over 1 year ago

0 Albert Xu1 over 1 year ago

TI__Mastermind 31315 points

Hi Richard,

I'm not sure if there's a specific reason for this. It is just in the design. Is there a need that you have for the 16 bit version?

0 Richard Staebler over 1 year ago in reply to Albert Xu1

Prodigy 50 points

Hello,

we are actual use the 16 bit version SN74LVC16373AZQLR in the BGA Microstar Junior Package (ZQL).
But this Package is EOL. And the TSSOP 48 from the 16 bit version is to big in this application. So we
want to replace the 16 bit version with two 8 bit version.

And now in the datasheet we have seen the slower switching characteristics at the 8 bit version at VCC1,8V.

It is interisting at which condition this switching characteristics at 1,8V are measuerd?

0 Emrys Maier over 1 year ago in reply to Richard Staebler

TI__Guru* 97016 points

Hello,

Richard Staebler said:
why are the max switching characteristics are so different between
SN74LVC373A and SN74LVC16373A at 1,8V ?

Since you are operating at 1.8-V supply, I would recommend that you look at the SN74AUC16373 as it has significant speed and signal integrity improvements over the older LVC family devices when operating at 1.8 V.

I filtered down a list of other possibilities here: Filtered '373 product list

Richard Staebler said:
why are the max switching characteristics are so different between
SN74LVC373A and SN74LVC16373A at 1,8V ?

While these two devices share a logic family making them similar, they are not identical, and they were developed at least 10 years apart:

I expect that the definers of the LVC16373 utilized the increased space of the larger 16-pin packages to provide stronger output drivers and thus lower delays for data bus applications.

Richard Staebler said:
It is interisting at which condition this switching characteristics at 1,8V are measuerd?

The conditions for the switching characteristics are always listed in the datasheet - if they are not, I would ask you to please post here so we can fix the error.

For the SN74LVC373A, the 1.8-V timing characteristics are taken with these conditions: