Is "read access speed" in datasheet matter for flash ic?

[debi]

Hi guys,

im trying to source a flash SST39vf040 90-nh-4C (plcc format)... unfortunatly i only can find SST39vf040 70-nh-4c. Looking at the datasheet there is only a difference between 90ns and 70ns read access speed. In case i put a 70-nh-4c, what is going to happen ? Sorry for this noob question.

https://html.alldatasheet.com/html-pdf/46905/SST/39VF040/1015/20/39VF040.html


cheers !

[BadeBhaiya]

You should be able to use it without a problem

The access time difference is quite insignificant.

[debi]

You should be able to use it without a problem

The access time difference is quite insignificant.

Hello,
thanks for your help
do you why they made different acces speed ic with so little difference if it's not that important ?

cheers

[wraper]

There is no issue using IC with lower access time. Access time is rated for worst case only, therefore it's easily possible that some 90ns IC actually can be faster than 70ns IC.

do you why they made different acces speed ic with so little difference if it's not that important ?

It is important if you need to operate them fast. It's not like they have a different silicon die. Manufacturer bins them in production and can sell faster ICs for more. If they produce more of faster ICs than market demands, manufacturers often sell faster ICs as lower grade.