Interfacing the AD22100 Temperature Sensor to a Low-Cost Single-Chip Microcontroller

Overview

This application note describes a cost-effective method for interfacing the Analog Devices AD22100 temperature sensor with microcontrollers such as the Intel 80C51 and 87C51. The AD22100 is a monolithic silicon sensor featuring a ratiometric voltage output that simplifies design by eliminating the need for a precision reference. The document details an integrating A/D architecture implemented primarily through firmware, which achieves 14-bit resolution and 0.1°C precision using minimal external components, including an LM393 comparator and a 74HC04 hex inverter. The note provides a simplified schematic, a detailed firmware flowchart, and the assembly code required for the conversion loop.

Referenced Parts