Low power NV memory has 4 Mbit capacity

The CY15B104Q 4-Mbit serial F-RAM features a 40-Mhz SPI interface and 2.0 to 3.6 V operating voltage range. The NV memory is organized as 512 K × 8 and offers endurance estimated at 100-trillion read/write cycles. 

Supply current is 300 µA maximum active at 1 MHz, 100 µA typical in standby and 3 µA in sleep mode. The chip has 10-year data retention at 85˚C, and 151 years at 65˚C. It comes in 8-pin SOIC or TDFN packages and operates over –40° to +85°C. $15.39 ea/100.