| Electronics > Beginners |
| Trying to find old 8k sram chips for HP-75c calculator pod |
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| RichardM:
Hi all Definitely a beginner. Trying to source compatible 8k sram chips for an old HP calculator (circa early to mid 80s) peripheral. The chips are marked as HM6264LFP-15 and as I understand they are 8k x 8bit 28pin soic. Pic attached. Any help greatly appreciated. Richard |
| wraper:
https://www.ebay.com/itm/1pcs-HM6264FP-15-64kBit-Static-RAM-Memory-HM6264-SO28L-HITACHI/263389473756?hash=item3d533c6bdc:g:q0wAAOSwi5RaNWtU EDIT. this likely will have higher power consumption in standby. https://www.aliexpress.com/item/Free-shipping-10PCS-LOT-HM6264ALFP-12T-HM6264LFP-10-HM6264ALFP-10-HM6264BLFP-10LT-HM6264ALFP-SOP-28-IC/32873394779.html?spm=2114.search0104.3.2.ede13981tbMYNp&ws_ab_test=searchweb0_0,searchweb201602_8_10065_10068_319_10059_10884_317_10887_10696_321_322_10084_453_10083_454_10103_10618_10307_10820_10821_10303_537_10302_536,searchweb201603_52,ppcSwitch_0&algo_expid=f18d8506-affa-4ca3-b79e-98f6a26c6969-0&algo_pvid=f18d8506-affa-4ca3-b79e-98f6a26c6969 https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=HM6264ALFP&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=HM6264lFP |
| wraper:
BTW there seem to be a corrosion under all ceramic caps on the picture. Maybe you don't need to replace RAM at all. |
| David Hess:
Any 28 pin JEDEC 8k x 8 SRAM should work if it is as fast or faster than the original parts. |
| Jay_Diddy_B:
Hi, These are standard 8K x 8 SRAM. However, the 'L' in the part number is used to indicate 10uW in Standby. 10uW is about 3uA at 3V. Is there a memory backup battery in this product? If these are powered from the battery, to retain the memory contents when the power is off, then you need to find the low standby versions of these chips. Regards, Jay_Diddy_B |
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