i have designed a circuit using AT24C64 ( I2C serial eeprom ) , now i want to know if there is any RAM IC that i could use instead of AT24C64 ?( should be 8pin )
If you want a small amount of RAM, then Dallas DS1302, 1307 comes to my mind. They are basically RTC chips with some bytes of RAM.
DS1200 is 1KB serial RAM
I searched google for "Serial RAM" and found quite a lot of links.
FRAM offers a unique set of features relative to other semiconductor technologies. Traditional mainstream semiconductor memories can be divided into two primary categories -- volatile and nonvolatile. Volatile memories include SRAM (static random access memory) and DRAM (dynamic random access memory). SRAMs and DRAMs lose their contents after power is removed from the electronic system. RAM type devices are very easy to use, and are high performing, but they share the annoying quirk of losing their mind when the lights go out.
Nonvolatile memories do not lose their contents when power is removed. However all of the mainstream nonvolatile memories share a common ancestry that derives from ROM (read only memory) technology. As you might guess, something called read only memory is not easy to write, in fact it's impossible. All of its descendants make it very difficult to write new information into them. They include technologies called EPROM (almost obsolete now), EEPROM, and Flash. ROM based technologies are very slow to write, wear out after being written a small number of times, and use a large amount of power to write.
FRAM offers features consistent with a RAM technology, but is nonvolatile like a ROM technology. FRAM bridges the gap between the two categories and creates something completely new -- a nonvolatile RAM.