PRODUCT DESCRIPTION
The UT28F256 amorphous silicon anti-fuse PROM is a high performance, asynchronous, radiation-hardened,
32K x 8 programmable memory device. The UT28F256 PROM features fully asychronous operation requiring no external clocks or timing strobes. An advanced radiation-hardened twin-well CMOS process technology is used to implement the UT28F256. The combination of radiation-hardness, fast access time, and low power consumption make the UT28F256 ideal for high speed systems designed for operation in radiation environments.

FEATURES
Programmable, read-only, asynchronous, radiation hardened, 32K x 8 memory
- Supported by industry standard programmer
45ns and 40ns maximum address access time (-55^oC to +125^oC)
TTL compatible input and TTL/CMOS compatible output levels
Three-state data bus
Low operating and standby current
  - Operating: 125mA maximum @25MHz
      · Derating: 3mA/MHz
  - Standby: 2mA maximum (post-rad)
Radiation-hardened process and design; total dose irradiation testing to MIL-STD-883, Method 1019
  - Total dose: 1E6 rad(Si)
  -  LET_TH(0.25) ~ 100 MeV-cm²/mg
  -  SEL Immune  >128 MeV-cm²/mg
  - Saturated Cross Section cm² per bit, 1.0E-11
  - 1.2E-8 errors/device-day, Adams 90% geosynchronous heavy ion
  - Memory cell LET threshold: >128 MeV-cm²/mg
QML Q & V compliant part
  - AC and DC testing at factory
Packaging options:
  - 28-lead 50-mil center flatpack (0.490 x 0.74)
  - 28-lead 100-mil center DIP (0.600 x 1.4) - contact factory
VDD: 5.0 volts +  10%
Standard Microcircuit Drawing 5962-96891