Holt Releases First ARINC 429 Quad Line Driver
ProductJanuary 28, 2026
ALISO VIEJO, Calif. Holt Integrated Circuits announced the launch of its HI-85104, what is says is the world's first quad ARINC 429 line driver, a part that Holt describes as enabling aerospace designers to achieve higher channel density while reducing board area, component count, and design complexity.
The HI-85104 integrates four fully independent ARINC 429 transmit channels into a compact 6 mm × 6 mm QFN package, replacing four discrete single-channel line drivers with a single device. Compared to traditional implementations, the HI-85104 can reduce board area by up to 30%, making it ideal for space-constrained, high-channel-count applications such as embedded LRUs, automated test equipment (ATE), and systems integration labs.
Each channel is independently protected to eliminate single-point failures. If a short circuit occurs on any channel, the remaining channels continue operating normally. The affected channel safely drives a null for the remainder of the message and automatically resets during the inter-message gap. All transmit outputs also support a high-impedance tri-state when powered on or off, allowing multiple line drivers to share a common ARINC bus in test and lab environments.
To simplify system integration, the HI-85104 supports 1.8 V, 2.5 V, 3.3 V, and 5 V digital I/O, enabling direct interfacing with a wide range of FPGAs and microcontrollers without level shifters. All analog circuitry operates from a single 3.3 V supply, using an integrated dual-polarity voltage doubler to generate ARINC-compliant output levels.
Transmit outputs include integrated 37.5 Ohm impedance matching resistors, eliminating the need for external resistors and simplifying layout. Built-in series fuses provide protection against high-current transients, while optional zero Ohm transmit outputs are available for applications requiring external lightning protection circuitry.
The HI-85104 pairs directly with Holt’s HI-3220 family of integrated ARINC 429 protocol ICs, providing a complete, compact transmit-and-receive solution for high-channel-count ARINC 429 systems.
“Customers have traditionally been required to use multiple single-channel line drivers to achieve higher channel counts. The HI-85104 replaces that approach with a single quad device, significantly reducing board area, component count, and design complexity while maintaining channel-level isolation,” said Sean Sleicher, Director of Business Development at Holt Integrated Circuits.
The HI-85104 is available in a 48-pin, 6 mm × 6 mm QFN package and supports an extended operating temperature range of –55°C to +125°C. Burn-in screening is available on select devices. Samples are available now by contacting [email protected].
For more information on Holt’s ARINC 429, CAN (ARINC 825), MIL-STD-1553, and aerospace interface solutions, contact Holt Integrated Circuits at (949) 859-8800, email [email protected], or visit www.holtic.com.
