SB040312025 – FORMALDEHYDE SENSOR SCHEMATIC BLOCK

This schematic block features the Sensirion SFA30‑D‑T, a high-precision electrochemical sensor module for detecting formaldehyde (HCHO) in the low parts-per-billion (ppb) range. It integrates a formaldehyde sensing cell together with a temperature- and humidity-compensating sensor and microprocessor, delivering a lifetime-calibrated digital output via I²C or UART.

Configured as a breakout-style module, this block gives designers direct access to the sensor’s I²C (SDA/SCL) or UART lines, plus power, ground, and an interface-select pin. Thanks to the sensor’s built-in compensation, it is highly stable over the long term and can operate reliably even in varying environmental conditions.

The SFA30 family is trusted in HVAC, air-purifier, and indoor-air-quality (IAQ) systems due to its low cross-sensitivity, long service life, and accurate ppb-level formaldehyde detection.

Key Features:

• Digital interface: I²C (primary) or UART (selectable)
• Formaldehyde detection range: 0 to 1,000 ppb
• Saturation limit: up to 5,000 ppb
• Resolution: 1 ppb
• Accuracy: ± 20 ppb or ± 20%, whichever is larger
• Low cross-sensitivity to ethanol and other common gases
• Response time: < 2 minutes typical
• Long service life: > 6 years under standard conditions
• Long-term drift: < 5 ppb or < 5% per year
• Operating temperature: 0 °C to +40 °C
• Supply voltage: 3.15 V to 5.5 V
• Typical current consumption: ~1 mA
• Includes integrated RH/temperature sensor for compensation
• Interface-select pin for choosing I²C or UART

Typical Applications:

• Indoor air quality (IAQ) monitors and HVAC systems
• Air purifiers and air-exchange units
• Smart-home environmental sensing
• Building safety systems for formaldehyde detection
• Portable or battery-based formaldehyde monitors
• Research and laboratory gas monitoring systems

By integrating this Quickboards schematic block, engineers can rapidly prototype a calibrated formaldehyde sensing system, reduce analog front-end complexity, and rely on a reliable, long-lifetime digital sensor with built-in temperature and humidity compensation.