The HI-8400 is a galvanically isolated 4-channel discrete-to-digital sensor designed to output sensor data via a Serial Peripheral Interface (SPI) or parallel bus interface. Galvanic isolation provides 800V isolation between each of the sensors and the logic interface. This is an ideal device for systems that must tolerate different grounds.


Each input is individually pin configurable as either GND/Open or Supply/Open (28V/Open). Discrete input thresholds are compliant to the Airbus ABD0100H and MIL-STD-704 specification. The part operates from a 3.3V (+/-5%) or 5.0V (+/-5%) digital supply and 28V analog supply for each isolated sensor.


A 1mA wetting current is sourced from the input network on each SENSE input when GND/Open mode is selected for that pin. The wetting current serves to prevent dry relay or switch contacts. A sensor output interrupt pin alerts the system to a change in sensor input, avoiding constant polling via SPI to check status.


All sense inputs are internally 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) with respect to the sensor return ground, without using external components.


The device is available in industrial −40oC to +85oC and extended −55oC to +125oC temperature ranges and comes in a 44-pin PQFP package.




  • Airbus ABD0100H and MIL-STD-704 standard compliant sensor thresholds
  • Sensor data outputs read through SPI or parallel bus
  • Interrupt generated on any change of sensor state
  • Galvanically isolated discrete-to-digital sensor providing 800V isolation between each sensor and the logic interface
  • Four discrete inputs, individually pin configurable as GND/Open or Supply/Open
  • Sense inputs lightning protected to RTCA/DO1060G, Section 22, Level 3
  • 5MHz Serial Peripheral Interface (SPI) allows daisychaining of parts for efficient board routing
  • Withstands inadvertent application of 115V AC/400Hz power to sense inputs 



  • Avionics discrete sensing applications



ADK-8400 Evaluation Board  –  800V Isolated Discrete Sensor

ADK-8400 Evaluation Board – 800V Isolated Discrete Sensor

The ADK-8400 Evaluation Board allows customers to evaluate the features of the 800V galvanically isolated HI-8400 four channel discrete sensor IC. Each input has full isolation from the digital domain and from the other sensor inputs. Sensor thresholds are internally set at Airbus ABD0100H levels and an SPI port is used to read sensor data.
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