An autonomous CCSDS packet generating ASIC for analog and digital telemetry

The Packetised Essential Telemetry Retrieval ASIC (PETRA) is a mixed analog/digital chip for retrieving sensor data on-board spacecraft, designed by Silicon Systems Ltd. One single PETRA can connect up to 40 digital and/or analog sensors which are periodically sampled. CCSDS Telemetry packets containing the data are automatically generated and can be delivered directly to the transfer frame generator or to an on-board processor. The packets are output serially, at a nominal baud rate of 9600 bps or 115.2 kbps, with the interface being directly compliant with both the Virtual Channel Multiplexer (VCA) and RS-232 type asynchronous serial interfaces. The PETRA is a 0.8 μm double-metal, double-poly CMOS mixed signal device with a die size of 26 mm². The dynamic power dissipation is 80 mW with a static dissipation of 30 mW. This paper introduces the advantages of using the PETRA in a spacecraft´s Data Handling System (DHS) compared to a traditional implementation. An overview of the PETRA functionality is presented, followed by a description of the device architecture. An outline of the design methodology is then followed by a discussion of the PETRA demonstration system