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Rad Hard 4 Megabit (512K x 8-Bit) CMOS SRAM Memory

Discontinued Product. Please contact the factory for the latest replacement.


Part Number(s): 33C408

DDC's 33C408 high-density 4 Megabit SRAM microcircuit features a greater than 100 krad (Si) total dose tolerance, depending upon space mission. Using DDC's radiation-hardened RAD-PAK® packaging technology, the 33C408 realizes a high density, high performance, and low power consumption. Its fully static design eliminates the need for external clocks, while the CMOS circuitry reduces power consumption and provides higher reliability. The 33C408 is equipped with eight common input/output lines, chip select and output enable, allowing for greater system flexibility and eliminating bus contention. The 33C408 features the same advanced 512K x 8-bit SRAM, high-speed, and low-power demand as the commercial counterpart.

DDC's patented RAD-PAK packaging technology incorporates radiation shielding in the microcircuit package. It eliminates the need for box shielding while providing the required radiation shielding for a lifetime in orbit or space mission. In a GEO orbit, RAD-PAK provides greater than 100 krad (Si) radiation dose tolerance. This product is available with screening up to Class S.


  • RAD-PAK® Technology radiation-hardened against natural space radiation
  • 524,288 x 8 bit organization
  • Total dose hardness:
    • >100 krad (Si), depending upon space mission
  • Excellent Single Event Effect
    • SELTH: > 68 MeV/mg/cm2
    • SEUTH: = 3 MeV/mg/cm2
    • SEU saturated cross section: 6E-9 cm2/bit
  • Package:
    • 32-Pin RAD-PAK® flat pack
    • 32-Pin Non-RAD-PAK® flat pack
  • Fast access time:
    • 20, 25, 30 ns maximum times available
  • Single 5V +/- 10% power supply
  • Fully static operation
    • No clock or refresh required
  • Three state outputs
  • TTL compatible inputs and outputs
  • Low power:
    • Standby: 60 mA (TTL); 10 mA (CMOS)
    • Operation: 180 mA (20 ns); 170 mA (25 ns); 160 mA (30 ns)




33C408 4 Megabit (512K x 8-Bit) CMOS SRAM Data Sheet


How Rad Hard Do You Need? The Changing Approach To Space Parts Selection?

Proton Transport An Examination of Model and Experimental Data For Space Environment Protons

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