The HI-8428-R is an 8-channel discrete-to-digital sensor fabricated with Silicon-on-Insulator (SOI) technology designed to interface with a Serial Peripheral Interface (SPI).


Each input is individually configurable as either GND/Open or Supply/Open (28V/Open). Discrete input thresholds and hysteresis are compliant with Airbus ABD0100H specification. In GND/Open mode, thresholds are set at 4.5V/10.5V, and in Supply/Open mode at 6V/12V.


The part operates from a 3.3V (+/- 5%) digital supply and 12V - 16.5V analog supply.


A 1mA wetting current is sourced from each SENSE input when GND/Open mode is selected for that pin. The wetting current serves to prevent dry relay or switch contacts.


All sense inputs are lightning protected to RTCA/DO160G, Section 22 Level 3 Pin Injection Test Waveform Set A (3 & 4), Set B (3 & 5A) and Set Z (3 & 5B) when used with the required external 3kΩ resistors. Levels 4 and 5 lightning protection can also be obtained by using the required external 3kΩ series resistor and a TVS at each SENSE input.


The device is available in industrial −40oC to +85oC and extended −55oC to +125oC temperature ranges and comes in a 16-pin, narrow body SOIC with exposed heat pad.


HI-8428-R is a drop-in replacement for the DEI1284.




  • Eight discrete inputs, individually configurable as GND/Open or Supply/Open (28V/Open)
  • Sense inputs lightning protected to RTCA/DO1060G, Section 22 Level 3, 4 and 5 Pin Injection Test Waveforms with minimal external components
  • 10MHz Serial Peripheral Interface (SPI) allows daisychaining of parts for efficient board routing
  • Withstands inadvertent application of 115V AC/400 Hz power to Sense inputs.
  • Airbus ABD0100H compliant
  • MIL-STD-704 compliant
  • Internal Self-Test mode checks analog comparators and logic
  • Robust CMOS Silicon-on-Insulator (SOI) technology
  • Industrial & extended temperature ranges available
  • Drop-in replacement for DEI1284



  • Avionics discrete sensing applications



ADK-8428-R: HI-8428-R Discrete-to-Digital Sensor Evaluation Board

ADK-8428-R: HI-8428-R Discrete-to-Digital Sensor Evaluation Board

The Holt HI-8428-R Evaluation Board demonstrates the features of the HI-8428-R, an 8-channel Ground/Open or 28V/Open discrete-to-digital sensor IC with SPI interface. The HI-8428-R is powered from 3.3V ± 5% VLOGIC and 12 to 16.5V VDD supply voltages. The device is configured and sensor data read by the SPI serial bus. Sensor input thresholds are fixed at Airbus specification levels. The EVM (Evaluation Module) contains a 16-bit, Freescale MC9S12XDT512 MCU, which is used to interface to a terminal emulator and control the HI-8428-R.
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