The M48Z512A, M48Z512AY 4 Mbit (512Kb x8) ZEROPOWER SRAM integrates a low power SRAM, a power-fail control circuit and a battery. It supports unlimited write cycles and retains data for 10 years in the absence of power.
The ST M48Z512A and M48Z512AY are 4‑Mbit (512 Kb × 8) ZEROPOWER® SRAMs that integrate an internal lithium battery, a CMOS SRAM array and a power‑fail control circuit. The devices provide unlimited write cycles, 10‑year data retention without power, and automatic write protection when the supply voltage falls out of tolerance.
The handbook includes absolute maximum ratings, operating modes, AC and DC characteristics, package mechanical data, and hardware hookup diagrams for both DIP and surface‑mount chip‑set solutions. It also details the write‑protect voltage ranges for each variant and the battery‑back‑up switchover voltage.
| Data retention time | 10 YEARS |
|---|---|
| Supply voltage range | 0.3 V to 7 V |
| Write‑protect voltage (M48Z512A) | 4.50 V < Vprp < 4.75 V |
| Write‑protect voltage (M48Z512AY) | 4.20 V < Vprp < 4.50 V |
| Battery backup switchover voltage | 3 V |
The write‑protect voltage for the M48Z512A must be between 4.50 V and 4.75 V.
Data can be retained for up to 10 years when power is absent.
The devices operate from 0.3 V up to 7 V supply voltage.
The battery backup switchover voltage is specified as 3 V.