RS-485/422 Avionics Transceiver Family with Controlled Slew Rate

Monday, August 29, 2011

Mission Viejo, CA (July 21, 2011) – Holt Integrated Circuits, a world leader in data bus IC’s for commercial and military avionics, announced today a new transceiver family meeting the TIA‑422-B and TIA-485-A specifications. The HI-4850 family provides customers with a range of options meeting all RS-485/422 application needs, including high and low speed, as well as full and half-duplex requirements.

All devices in the family offer extended power supply range (3.0V to 5.5V), controlled slew rate and a wide common mode voltage range (-15V to +15V). Slew rate is optimized for device speed. Low speed devices target data rates between 1 and 2 Mbps and high speed devices target 10 to 12 Mbps. Driver slew rate control and pre-emphasis ensure optimum performance in environments having strict EMI/EMC requirements, such as avionics flight controls and industrial automation. Each device delivers at least ± 1.54V and ± 2.45V output drive at worst-case supply voltages of 3.0V and 4.5V respectively, over an extended temperature range of −55oC to +125oC into a differential load of 54Ω and 100pF.

The receiver offers true Fail-Safe operation, providing 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 kΩ, supporting up to 192 nodes per bus.

The HI-4850, HI-4851 and HI-4852 are optimized for lower data rates, and are ideal for applications requiring runs up to 1,000 ft at 1 Mbps. 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 optimized for high data rates and will operate at 12 Mbps for runs up to 1,000 ft. Higher data rates are possible for shorter runs. This feature, along with the optimized slew rate control, makes these devices ideal for applications requiring high data rates such as MMSI (EBR-1553) or industrial applications such as Profibus. The HI-4853 operates half duplex whereas the HI‑4854 and HI-4855 provide full duplex operation. Multiple package options are offered, including industry standard SO-8 pinouts. The HI-4852 and HI-4855 are available in compact 4mm x 4mm QFN-16 packages.

“Holt’s HI-4850 family provides the capability to meet virtually any RS-485/422 application requirement,” said Anthony Murray, Director of Business Development at Holt. “Specialized features such as targeted slew rate control and a wide common mode voltage range ensure reliable and superior performance over a broad range of operating conditions”.

To request information on Holt’s ARINC 429, MIL-STD-1553 and other aerospace products, readers should contact Holt at (949) 859-8800, by e-mail at, or visit the Holt Web site at

About Holt Integrated Circuits

Located in Mission Viejo, CA, Holt Integrated Circuits is a major supplier of ICs for avionics and military data bus and display applications.  The company’s products are specified by more than 400 manufacturers worldwide and are employed in flight control, navigation, engine management, communications, safety equipment, and in-flight entertainment systems.

Holt’s range of ICs supporting the ARINC 429 standard is the widest in the industry, and its display drivers offer high-voltage operation as well as innovative design features to enhance ease of use and testability.  Holt’s transceivers for MIL-STD-1553 applications are recognized as the industry’s smallest and have the lowest power consumption.  In addition, Holt also offers MIL-STD-1553 protocol ICs, Manchester encoder/decoders and interface transformers.  Select products are available to DSCC SMD specifications.  Holt also offers product compliant to the European Union "RoHS Directive 002/95/EC".

Holt Integrated Circuits is ISO 9001:2008 registered and is a STACK certified supplier.