Description
The UL635H256 has two separate modes of operation: SRAM mode and nonvolatile mode. In SRAM mode, the memory operates as an ordinary static RAM. In nonvolatile operation, data is transferred in parallel from SRAM to EEPROM or from EEPROM to SRAM. In this mode SRAM functions are disabled.

Features
High-performance CMOS non-volatile static RAM 32768 x 8 bits
35 and 45 ns Access Times
15 and 20 ns Output Enable Access Times
ICC= 8 mA typ. at 200 ns Cycle Time
Automatic STORE to EEPROM on Power Down using external capacitor
Software initiated STORE
Automatic STORE Timing
106 STORE cycles to EEPROM
100 years data retention in EEPROM
Automatic RECALL on Power Up
Software RECALL Initiation
Unlimited RECALL cycles from EEPROM
Wide voltage range: 2.7 ... 3.6 V (3.0 ... 3.6 V for 35 ns type)
Operating temperature range:
  0 to 70 °C
  -40 to 85 °C
QS 9000 Quality Standard
ESD characterization according (MIL STD 883C M3015.7-HBM)
Package: SOP28 (330 mil)