UL635H256 is a high-performance CMOS non-volatile static RAM with a storage capacity of 32768 x 8 bits, 35 and 45 ns access times, 8 mA ICC, and automatic store and recall functions. The product features a wide voltage range and high quality standards.
The UL635H256 combines a high‑speed static RAM with an integrated EEPROM for non‑volatile storage. It operates with access times of 35 ns or 45 ns and supports automatic STORE to EEPROM on power‑down using system capacitance, while RECALL occurs automatically on power‑up.
The device is supplied in a SOP‑28 (330 mil) package, works over a 2.7 V‑3.6 V supply range, and meets QS‑9000 quality and RoHS standards. Detailed electrical characteristics, timing diagrams, and pin descriptions are provided for designers.
| Access Time | 35 ns / 45 ns |
|---|---|
| Output Enable Access Time | 15 ns / 20 ns |
| Supply Voltage | 2.7 V – 3.6 V (3.0 V – 3.6 V for 35 ns type) |
| Package | SOP‑28 (330 mil) |
| ESD Protection | > 2000 V |
| Data Retention | 100 years in EEPROM |
The device provides two access‑time options: 35 ns or 45 ns.
It automatically stores the SRAM contents to the integrated EEPROM during power‑down using the system’s stored charge.
The part operates from 2.7 V to 3.6 V (3.0 V to 3.6 V for the 35 ns version).
It is supplied in a SOP‑28 package (330 mil).