Description

This reference design is a compact implementation of 96 isolated digital input channels using the ISO1212: an isolated digital input receiver. This design shows the current limit feature of the ISO1212 device which has better thermal performance than traditional optocoupler solutions. This design makes a digital input board with multiple channels more compact and decreases board temperature (less than 50 °C). A MUX and decoder with the ISO1212 device decreases the number of pins of the microcontroller from 96 to 8. The design was tested with 100-kHz input signals (200- kbit) per channel. The design uses less than 7.3 W of input power which results in less heat dissipation. All signals are designed to withstand ESD: EFT: and surge events according to IEC6100-4.