MISSION VIEJO, Calif., 21 Aug. 2011. Holt Integrated Circuits in Mission Viejo, Calif., is introducing the HI-3717 single-chip integrated circuit for the ARINC 717 flight data recorder avionics databus for digital flight data recorder applications in the recorder itself, the data acquisition unit, or the quick access recorder.
The HI-3717 communicates with an external microcontroller via a four-wire serial peripheral host interface (SPI) and provides selectable Harvard bi-phase (HBP) and bi-polar return-to-zero (BPRZ) channels with encoders and decoder, as well as dedicated line drivers and line receivers for direct connection to the ARINC 717 bus.
ARINC 717, which supersedes ARINC 573, is a flight data recorder output format. It adds several bit rates and frame sizes, and also provides for an alternate output data stream identical to the primary HBP-encoded stream, except that it is encoded in BPRZ format -- he same as ARINC 429.
The Holt HI-3717 includes an on-chip DC/DC converter, requiring one 3.3-volt supply to operate. The chip generates all voltage levels necessary for the BPRZ and HBP channels, while its nine programmable bit rates correspond to 32, 64, 128, 256, 512, 1024, 2048, 4096, and 8192 words per second.
The receive and transmit channels have 32-bit-by-12-word FIFOs that enable the external host to take a hands off approach and perform other tasks without frequent buffer servicing. Dedicated FIFO status flags are provided in both registers and external pins. The device also offers programmable slew rates on the transmitters of 1.5, 7.5, and 10 microseconds, dedicated SPI instruction set, digital transmitter outputs and frame/subframe word count indicator.
The HI-3717 uses a proprietary synchronization method for correct synchronization. The devices comes in a 7-by-7-millimeter, 44-pin, QFN package or a 44-pin PQFP. For more information contact Holt Integrated Circuits online at www.holtic.com.