This Analog Devices circuit note describes the CN-0429 reference design for an electrochemical gas measurement system using the ADuCM355 microcontroller.
The CN-0429 circuit note presents a reference design that integrates the ADuCM355 Precision Analog Microcontroller with a chemical sensor interface to create an electrochemical gas measurement system. It explains the sensor biasing, diagnostics, and signal‑conditioning circuitry, and provides design equations for setting the DAC outputs and transimpedance amplifier.
The document also lists the required evaluation boards (EVAL‑CN0429‑EBZ sensor board, EVAL‑M355‑ARDZ‑INT shield, and EVAL‑ADICUP3029 Arduino‑compatible platform), describes system setup, communication interfaces, and test procedures for evaluating sensor performance, including CO concentration measurements and health diagnostics.
| Recommended VZERO voltage | 1100 mV |
|---|---|
| ADC input range | ±900 mV |
| Low‑power DAC resolution | 12‑bit for VBIAS, 6‑bit for VZERO |
| Microcontroller used | ADuCM355 Precision Analog Microcontroller with Chemical Sensor Interface |
The design uses the ADuCM355 Precision Analog Microcontroller with a chemical sensor interface.
The VZERO voltage should be set to 1100 mV.
The SPI interface is recommended when the lowest possible supply current is critical.