Application of High-Precision, Low-Power ADCs (CM1103/CM1106) in Industrial Automation

1. Introduction

Architecture Diagram

The CM1103/CM1106 are highly integrated, high-precision, low-power, and low-cost ADCs introduced by Simu Microelectronics. With a sampling resolution of up to 7 µV, they can meet the requirements of most temperature sensor sampling applications. Their input impedance, reaching several megaohms, allows the ADCs to be directly connected to most resistive sensors without degrading sensor accuracy.

The CM110x family provides both I²C and SPI interfaces, making it easy for customers to interface with different processors. In addition, the CM1106 integrates a high-precision internal temperature sensor, which can be directly used for on-board temperature measurement and cold-junction compensation for thermocouples.

2. CM110x Features

• Single-supply operation: 2.5 V to 5.5 V

• Ultra-low power consumption: 270 µA (continuous conversion mode)

• Sleep current: 2 µA

• Programmable output data rate: 6.25 SPS to 2 kSPS

• Integrated high-precision voltage reference: 10 ppm/°C

• Programmable analog input ranges: ±0.256 V to ±6.144 V

• High-precision internal temperature sensor (CM1106)

• Internal programmable comparator (CM1103)

• 4 single-ended inputs / 2 differential input channels
  
  

3. Solution Overview

With the rapid development of industrial automation and increasing levels of factory intelligence, industrial automation instruments have in recent years been transitioning from analog to digital systems. With the adoption of microcontrollers and application-specific integrated circuits, industrial automation products are gradually evolving into intelligent devices.

Temperature is a critical parameter in industrial production, and temperature sensors play a vital role across the entire field of industrial automation. Based on different sensing technologies, a wide variety of temperature sensors are available, including infrared temperature sensors, resistance temperature detectors (RTDs), thermistors, and thermocouples. These temperature measurement applications are particularly well suited for signal conditioning and data acquisition using the CM110x family.

Beyond temperature sensing, the inherent advantages of the CM110x devices also make them ideal for a wide range of industrial sensing applications, such as resistive level sensors, resistive gas sensors, water quality analysis, and turbidity meters. These sensors typically have high output impedance and relatively low sensitivity, often requiring high-precision operational amplifiers for signal conditioning and amplification.

4. Product Advantages

The CM110x family combines high input impedance, high precision, and low power consumption, offering significant advantages in a wide range of industrial sensing applications. These features help customers increase the integration level of industrial transmitters while reducing overall system cost and power consumption.