Avionics databus transceivers for RS-485/422 applications over long cable runs introduced by Holt
MISSION VIEJO, Calif., 24 July 2011. Holt Integrated Circuits Inc. in Mission Viejo, Calif., is introducing HI-4850 family of avionics transceivers for RS-485/422 applications over long cable runs and in electrically noisy environments. The Holt HI-4850 transceivers meet TIA 422-B and TIA-485-A specifications, and offer high and low speed, as well as full and half-duplex requirements.
All devices in the HI-4850 family offer 3-to-5.5-volt power supply ranges , controlled slew rate, and a common mode voltage range of -15 to 15 volts. Low-speed devices are for applications with data rates between 1 and 2 megabits per second, and high speed devices target 10 to 12 megabits per second.
Driver slew rate control and pre-emphasis are for applications like such as avionics flight controls and industrial automation that have strict electromagnetic interference and electromagnetic compatibility (EMI/EMC) requirements.
Each device delivers at least plus-or-minus 1.54-volt and plus-or-minus 2.45-volt output drive at worst-case supply voltages of 3 and 4.5 volts in temperatures from -55 to 125 degrees Celsius into a differential load of 54 ohms and 100 pF.
The receiver has a guaranteed logic high output when the bus is open-circuit, short-circuit or idle (terminated but not driven). The receiver minimum input resistance is 80 kilo-ohms, supporting as many as 192 nodes per bus.
The HI-4850, HI-4851 and HI-4852 are for cable runs as long as 1,000 feet with data throughput of 1 megabit per second. The HI-4850 operates half duplex, whereas the HI-4851 and HI-4852 provide full duplex options.
The HI-4853, HI-4854 and HI-4855 are for data rates of 12 megabits per second on runs as long as 1,000 feet. Higher data rates are possible for shorter runs. For more information contact Holt Integrated Circuits online at www.holtic.com.
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