HI-8435: 32-Channel Discrete-to-Digital Detector IC with SPI Interface and Integrated Lightning Protection

the HI-8435 is part of Holt Discrete to digital sensor family, manufactured with Silicon-on-Insulator (SOI) technology for rugged, lock-free operation. The device has 32 discrete detection channels, divided into 4 banks of 8 inputs, each bank independently configurable to detect GND/Open or 28V/Open levels. Thresholds and hysteresis are programmable in steps of 0.5V from 2V to 21V.

This device is ideal for use in applications requiring a large number of sensing channels, for example “door open” and “wheels up” indicators. A 32-channel solution can be easily implemented using a single device, or the number of channels can be increased by controlling a number of devices on a single SPI bus using individual chip selects . Further space saving is achieved through built-in lightning protection, implemented without the need for external components. All discrete input thresholds comply with Airbus specification ABD0100H.

at Holts Discrete to digital sensor the family also includes HI-8400, a discrete-to-digital 4-channel galvanically isolated sensor offering 800 V isolation between each sensor and the logic interface. This device is useful in applications requiring a high level of fault tolerance, where critical components must be isolated from data bus faults.


● Selectable 32-channel detection operation, GND/Open or 28V/Open

● Thresholds and hysteresis programmable in steps of 0.5 V from 2 V to 21 V

● Detection inputs protected against lightning

● 20 MHz Serial Peripheral Interface (SPI)

● Airbus ABD0100H compliant

● Robust Silicon-on-Insulator (SOI) CMOS technology

● Industrial and extended temperature ranges available

Development kits with sample software are available for most Holt discrete-to-digital family devices:

ADK-8435: 32-Channel Discrete-to-Digital Sensor Evaluation Board

ADK-8400: 800 V galvanically isolated 4-channel discrete sensor IC