Bohemia, New York
DDC's BU-61582/83 radiation hardened version of its ACE MIL-STD-1553 data bus terminal is intended for use on launch vehicles, satellites, space stations, the space shuttle and other extra-terrestrial vehicles. Implemented in Honeywell's 0.8 micron RICMOS (Radiation-Insensitive CMOS) process, it retains all of the flexibility of the ACE family, including the ability to be configured as a bus controller (BC), remote terminal (RT) or monitor terminal (MT).
While the MIL-STD-1553 serial data bus was primarily developed for military avionic use, it is now widely used in space applications, such as commercial satellites. However, the additional requirements of radiation hardness and high reliability mean that special attention has to be paid to the process technology of the product.
The BU-61582 is available with or without DDC's bipolar transceivers in voltage options of +5V/-15V or +5V/-12V. Transceiverless options may be used with an external electrical or fibre-optic transceiver. DDC also offers the BU-65691 BC/RT.MT chip, which may be used with external transceivers and RAM.
The BU-61582 brings the full range of features of the ACE (Advanced Communications Engine) technology to customers requiring radiation tolerance and higher reliability characteristics necessary for space applications. It uses DDC's proprietary JRAD protocol chip and a 32k x 8 RAM.
Units with the transceivers can withstand a total gamma ray dose of 70 Krads and provide gamma ray dose rate characteristics of 2.0 x 107 rads (Si)/sec with no upset. A gamma dose rate as high as 1.0 x 1010 is tolerated with 25µs recovery.
Neutron fluence tolerance is 2 x 1013 neutrons/cm2. Because the digital components are RICMOS and the transceivers are bipolar, the BU-61582 hybrid is inherently immune to radiation-induced latch-up.
Transceiverless versions of the BU-61582 exhibit higher radiation tolerance, with total gamma dose capability of 1.0 Mrad, gamma dose rate survivability of 1.0 x 1012 rads (Si)/sec and neutron fluence tolerance of up to 1014 neutrons/cm2.
The 32k x 8 RICMOS RAM is utilized in a shared RAM microprocessor interface as if it were configured as 16k x 16. Package choices are 70-pin DIP or 70-pin flat pack for the BU-61582 or 196-pin ceramic quad flat pack for the BU-65621.
Customers can specify the reliability screening level they require, from Class K (formerly Class S, "full" space-level). This includes element evaluation, X-ray inspection, non-destructive 100% wire bond pull test, 320 hours burn-in, SEM micrographs, and particle-impact noise detection (PIND) testing. Customized screening levels are also possible and particular getters, which attract and hold foreign bodies inside the hybrid case, may be included.
