INTRODUCTION
The UT7C138 and UT7C139 are high-speed radiationhardened CMOS 4K x 8 and 4K x 9 dual-port static RAMs. Arbitration schemes are included on the UT7C138/139 to handle situations when multiple processors access the same memory location. Two ports provide independent, asynchronous access for reads and writes to any location in memory.

FEATURES
❐ 45ns and 55ns maximum address access time
❐ Asynchronous operation for compatibility with industry
   standard 4K x 8/9 dual-port static RAM
❐ CMOS compatible inputs, TTL/CMOS compatible output
   levels
❐ Three-state bidirectional data bus
❐ Low operating and standby current
❐ Radiation-hardened process and design; total dose
   irradiation testing to MIL-STD-883 Method 1019
   - Total-dose: 1.0E6 rads(Si)
   - Memory Cell LET threshold: 85 MeV-cm2/mg
   - Latchup immune (LET >100 MeV-cm2/mg)
❐ QML Q and QML V compliant part
❐ Packaging options:
   - 68-lead Flatpack
   - 68-pin PGA
❐ 5-volt operation
❐ Standard Microcircuit Drawing 5962-96845