U634H256 is a high-performance, non-volatile CMOS static RAM from Microchip. It has 32768x8 bits, 25, 35 and 45ns access times, 10, 15 and 20ns output enable access times, 15mA typical ICC, automatic storage to EEPROM, no external capacitor.
The U634H256 is a fast static RAM (25, 35, or 45 ns) that incorporates an electrically erasable PROM (EEPROM) element in each memory cell. It operates in two modes: standard SRAM mode and nonvolatile mode where data transfers between the SRAM and EEPROM.
| Memory Capacity | 32K x 8 bits |
|---|---|
| Access Times | 25, 35 and 45 ns |
| Output Enable Access Times | 10, 15 and 20 ns |
| Supply Current (typical) | 15 mA at 200 ns Cycle Time |
| Data Retention | 10 years in EEPROM |
| Operating Temperature (C-Type) | -40 to 70°C |
| Packages | SOP32, PDIP32 |
Data transfers from SRAM to EEPROM automatically upon power down using charge stored in an external capacitor.
Yes, transfers from EEPROM to SRAM take place automatically on power up.
The absolute maximum rating for Power Supply Voltage is 7 V.