Integrated circuits that would perform a variety of analog-signal, digital- signal, and power input/output functions have been proposed. Conceived for use as versatile, fault-tolerant interfaces among components and subsystems of spacecraft, these multifunction integrated circuits could also be attractive for similar uses in a variety of terrestrial systems, including ground vehicles, aircraft, industrial facilities, and communication systems.
- A transceiver for spread-spectrum radio communication with other such integrated circuits;
- A microprocessor functioning as a central processing unit (CPU) or digital signal processor (DSP);
- Volatile and/or nonvolatile memory circuits;
- Analog input circuits, including signalconditioning amplifiers and analog-todigital converters (ADCs);
- Analog output circuits, including digital- to-analog converters (DACs);
- Digital input/output (I/O) circuits;
- Power-switching circuits containing high-power metal oxide semiconductor field-effect transistors (MOSFETs).
The multifunction integrated circuit would serve as both a power and a signal interface for the subsystem or component to which it was connected. If, for example, the subsystem were a motor, then the multifunction integrated circuit could receive motor commands transmitted by radio from a different subsystem, switch the motor power on and off as needed, and possibly transmit data on the operation of the motor (e.g., shaft-angle, speed, voltage, and/or current readings) to another subsystem. Other than wire connections for a radio-communication antenna and for the motor or other subsystem served, the only wire connections between the multifunction integrated circuit and the rest of the system would be those needed to supply power to the circuit and subsystem.
All data and control signals — both digital and analog — would be transmitted via the radio links. By serving as standardized interfaces that would eliminate the need for signal wiring, these multifunction integrated circuits could make it easier to design and construct multinode systems that could be reconfigured in software (and perhaps in hardware). With respect to digital communication among subsystems, each of the multifunction integrated circuits would constitute a node of a wireless communication network. By use of previously developed Ethernet (or equivalent) and spread-spectrum protocols, babbling (uncontrolled transmission) by one of the nodes of the network would be prevented from interfering with communication among the other nodes.
This work was done by James Dillon and Michael Newell of Caltech for NASA’s Jet Propulsion Laboratory.
This Brief includes a Technical Support Package (TSP).
Multifunction Input / Output Integrated Circuits
(reference NPO-30212) is currently available for download from the TSP library.
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Overview
The document presents a technical support package detailing the development of multifunction input/output integrated circuits (I/O ICs) designed for use in spacecraft, specifically under the auspices of NASA and the Jet Propulsion Laboratory (JPL). The work, attributed to inventors James W. Dillon and Michael A. Newell, focuses on creating a single-chip solution that integrates various functionalities necessary for spacecraft operations.
Key features of the proposed system include a wireless interface utilizing spread spectrum radio frequency (RF) technology, which enhances flexibility and reliability while reducing the complexity of wiring. This wireless network can support data rates of up to 10 MB/s and is designed to operate efficiently in space environments, where traditional wiring can be cumbersome and prone to failure. The document emphasizes the importance of a fault-tolerant design, ensuring that if one component fails, it does not disrupt the entire network.
The integrated circuit is envisioned to include a microprocessor or digital signal processor (DSP), memory (both volatile and non-volatile), and the capability to boot over the RF network. It can manage various spacecraft components, such as sensors, cameras, and motors, allowing for a reprogrammable interface that can adapt to different operational needs. This adaptability is crucial for modern spacecraft, which often require versatile systems to handle diverse tasks.
Additionally, the document highlights the potential for radiation-hardened or radiation-tolerant designs, making the technology suitable for a wide range of spacecraft applications, including those exposed to harsh space conditions. The reduction in wiring not only simplifies the design of large spacecraft but also benefits smaller systems, such as nano spacecraft and science craft.
The overall goal of this innovation is to create a comprehensive, efficient, and reliable I/O interface that can significantly streamline spacecraft operations, reduce weight and complexity, and enhance the ability to connect various subsystems seamlessly. The document serves as a technical disclosure of the novel approach to spacecraft communication and control, aiming to address existing challenges in the field of aerospace engineering.
