3

HLX6228

Total Dose

rad(Si)

Transient Dose Rate Upset

rad(Si)/s

Transient Dose Rate Survivability

rad(Si)/s

Soft Error Rate

upsets/bit-day

Neutron Fluence

Parameter

Limits (2)

Test Conditions

RADIATION HARDNESS RATINGS (1)

Units

°C

Total Ionizing Radiation Dose

The SRAM will meet all stated functional and electrical

specifications over the entire operating temperature range

after the specified total ionizing radiation dose. All electri-

cal and timing performance parameters will remain within

specifications after rebound at VDD = 3.6 V and T =125

°C

extrapolated to ten years of operation. Total dose hard-

ness is assured by wafer level testing of process monitor

transistors and RAM product using 10 KeV X-ray and Co60

radiation sources. Transistor gate threshold shift correla-

tions have been made between 10 KeV X-rays applied at

°C and gamma

rays (Cobalt 60 source) to ensure that wafer level X-ray

testing is consistent with standard military radiation test

environments.

Transient Pulse Ionizing Radiation

The SRAM is capable of writing, reading, and retaining

stored data during and after exposure to a transient

ionizing radiation pulse, up to the specified transient

dose rate upset specification, when applied under rec-

ommended operating conditions. To ensure validity of all

specified performance parameters before, during, and

after radiation (timing degradation during transient pulse

radiation (timing degradation during transient pulse ra-

diation is

≤10%), it is suggested that stiffening capaci-

tance be placed on or near the package VDD and VSS,

with a maximum inductance between the package (chip)

and stiffening capacitance of 0.7 nH per part. If there are

no operate-through or valid stored data requirements,

typical circuit board mounted de-coupling capacitors are

recommended.

(1) Device will not latch up due to any of the specified radiation exposure conditions.

(2) Operating conditions (unless otherwise specified): VDD=3.0 V to 3.6 V, TA=-55

°C to 125°C.

1 MeV equivalent energy,

°C

°C, Adams 90%

worst case environment

Pulse width

≤50 ns, X-ray,

°C

Pulse width

≤1 µs

RADIATION CHARACTERISTICS

The SRAM will meet any functional or electrical specifica-

tion after exposure to a radiation pulse up to the transient

dose rate survivability specification, when applied under

recommended operating conditions. Note that the current

conducted during the pulse by the RAM inputs, outputs,

and power supply may significantly exceed the normal

operating levels. The application design must accommo-

date these effects.

Neutron Radiation

The SRAM will meet any functional or timing specification

after exposure to the specified neutron fluence under

recommended operating or storage conditions. This as-

sumes an equivalent neutron energy of 1 MeV.

Soft Error Rate

The SRAM is capable of meeting the specified Soft Error

Rate (SER), under recommended operating conditions.

This hardness level is defined by the Adams 90% worst

case cosmic ray environment for geosynchronous orbits.

Latchup

The SRAM will not latch up due to any of the above

radiation exposure conditions when applied under recom-

mended operating conditions. Fabrication with the

SIMOX substrate material provides oxide isolation be-

tween adjacent PMOS and NMOS transistors and elimi-

nates any potential SCR latchup structures. Sufficient

transistor body tie connections to the p- and n-channel

substrates are made to ensure no source/drain snapback

occurs.