Author Topic: Available replacement for SRAM HM62256BLFP (low standby power ~ 1uW)?  (Read 1425 times)

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Offline carl_lab

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I try to find an available replacement for SRAM Hitachi HM62256BLFP (low standby power ~ 1uW +/-).
3V, 5V tolerant
2.7V data retention voltage

Datasheet of original:
http://ee-classes.usc.edu/ee459/library/datasheets/hm62256.pdf

Can anybody help?

 

Offline YTSOC

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why not just order it of ebay?
 

Offline carl_lab

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Can't buy from ebay by business account.
 

Offline ap

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    • ab-precision
Digikey e.g. has them, even lower typ. standby current.
Metrology and test gear and other stuff: www.ab-precision.com
 
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Offline carl_lab

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Digikey e.g. has them, even lower typ. standby current.
Can you provide the link, please?
 

Online JFJ

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The search results for SRAM 32K on the Farnell web site provides several equivalents to the Hitachi SRAM, e.g:

http://de.farnell.com/lyontek/ly62256sl-55lli/sram-256k-32kx8-2-7-5-5v-28soic/dp/2253655
 

Offline carl_lab

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Great, thank you!
Can I use faster than original (55ns instead of 70ns)?
 

Online Tomorokoshi

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Great, thank you!
Can I use faster than original (55ns instead of 70ns)?

It should be fine when it comes to data access.

Note that there are other parameters that have timing changes. For instance, tCHG and tWHZ. However, these shouldn't be a problem unless it is being accessed by something outside of a typical processor given the (for these days) relatively slow access.

Also compare the output load rating to the original part. This one is listed as "CL = 50pF + 1TTL". For instance, if the slower original is rated to 100pF for it's timing, etc. then it may all balance out anyway.
 
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Online JFJ

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Can I use faster than original (55ns instead of 70ns)?

The address access time quoted is the maximum access time (no minimum time is specified). The price for the 70ns version is exactly the same:

http://de.farnell.com/lyontek/ly62256sl-70ll/sram-256k-32kx8-2-7-5-5v-28sop/dp/2253657

That might suggest that the 55ns and 70ns versions are identical, with just the markings changed.
 
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Offline carl_lab

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Also compare the output load rating to the original part. This one is listed as "CL = 50pF + 1TTL".
For instance, if the slower original is rated to 100pF for it's timing, etc. then it may all balance out anyway.
Exactly!
Dataheet HM62256B:
Quote
HM62256B-5: 1 TTL Gate + CL (50 pF)(Including scope & jig)
HM62256B-7/8:  1 TTL Gate + CL (100 pF)(Including scope & jig)
« Last Edit: July 28, 2017, 07:04:28 pm by carl_lab »
 


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