HI-8429

November 2015 HI-8429 8-Channel GND/Open or Supply/Open Sensor with Programmable Thresholds and SPI Interface GENERAL DESCRIPTION The HI-8429 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 are programmable in the range of 2V to 12V. An SPI bus is used to configure the sensors and to read sensor data . The part operates from a 3.3V (±5%) digital supply and 12V to 15V analog supply. 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. An optional debounce circuit also ensures sensor outputs respond correctly to mechanical sensor inputs. A sensor output interrupt pin alerts the system to a change in sensor input, avoiding constant...