|x 8 Radiation Hardened Programmable Read Only Memory (PROM) � 3.3V
Other Read/Write Cycle Times to 125�C) SMD Number Pending Asynchronous Operation TTL Compatible I/O Single V �5% Power Supply Low Operating Power Packaging Options 28-Lead Flat Pack x 0.720")
Radiation Fabricated with Bulk CMOS 0.8 �m Process Total Dose Hardness through 2x105 rad(Si) Neutron Hardness through 1x1012 N/cm2 SEU Immune (No Latches) Latchup Free
General Description The x 8 radiation hardened PROM is pinout, function and package compatible with commercial 28C256 series x 8 EEPROMs, such as SEEQ 28C256 and Atmel AT28C256. The PROM is fabricated with BAE SYSTEMS' QML-qualified radiation hardened technology, and is designed for use in systems operating in radiation environments. The radiation hardened Oxide-Nitride-Oxide (ONO) anti-fuse technology features 0.8 micron, 5 V transistors in the data path, and 1.0 micron, high voltage N and PFETs in the programming path circuitry. The PROM operates over the full military temperature range, requires a single � 5% power supply, and is available with TTL compatible I/O. Power consumption is typically 15 mW/MHz in operation and is less than 10 mW/MHz in the low power disabled mode. The PROM operation is fully asynchronous, with an associated typical access time of 100 nanoseconds. Synchronous operation is also possible using as a clock. BAE SYSTEMS' enhanced bulk CMOS technology is radiation hardened through the use of advanced and proprietary design, layout, and process hardening techniques.
� Address input pins that select a particular eight-bit word within the memory array. � Bi-directional data pins that serve as data outputs during a read operation and as data inputs during a write operation. � Negative output enable, when at a high level, holds the data output drivers in a high impedance state. In programming mode, with OE high and CE low, data driver state is in "Data-In" to enable programming.
� Chip enable, when at a low level with OE at low level, allows normal operation. When at a high level, CE forces the data output drivers in a high impedance state.
Mode Read Tristate Standby Program Inputs(1),(2) CE Low VDD High Low OE Low High X High VPP VDD � 0.5V I/O Data-Out High-Z Data-In Power (3) Active Standby1 Standby2 Programming
Notes: 1) VIN for don't care (X) inputs = VIL or VIH. 2) High: VIN 2.2 V for TTL inputs. Low: VIN 0.8 V for TTL inputs. 3) Minimum IDD is drawn when standby mode is implemented with = VDD(standby1 power). 4) Programming needs to be done using VDD = 5V.
Applied Conditions(1) Storage Temperature Range (Ambient) Operating Temperature Range Positive Supply Voltage Input Voltage(2) Output Voltage(2) Power Dissipation(3) Lead Temperature (Soldering 5 sec) Electrostatic Discharge Sensitivity(4)
1) Stresses above the absolute maximum rating may cause permanent damage to the device. Extended operation at the maximum levels may degrade performance and affect reliability. All voltages are with reference to the module ground leads. 2) Maximum applied voltage shall not exceed V. 3) Guaranteed by design; not tested. 4) Class as defined in MIL-STD-883, Method 3015.
Symbol VDD VPP GND TC VIL VIH Parameters(1) Supply Voltage Programming Voltage Supply Voltage Reference Case Temperature Input Logic "Low" - TTL Input Logic "High" - TTL Minimum +3.14 VDD Maximum +3.46 VDD Units Volt Celsius Volt1) All voltages referenced to GND. 2) VPP = VDD during non-programming mode.
Power shall be applied to the device only in the following sequences to prevent damage due to excessive currents: Power-Up Sequence: GND, VDD, Inputs Power-Down Sequence: Inputs, VDD, GND