7 Sensor Input

Capacitive and Conductive Sensor Input.

The MTCH9010 Evaluation Kit includes two sensor PCBs intended to give the user a quick introduction to the MTCH9010 and its capabilities. The goal is to have a rapid prototyping platform for users to evaluate their own sensor designs.

The MTCH9010 detects liquids by measuring the capacitive or conductive levels of the corresponding connected sensors. Only one sensing mode can be active at a time.
Tip: For detailed sensor design considerations and guidelines, see the MTCH9010 data sheet.

Capacitive Sensor Input

The MTCH9010 Evaluation Kit includes a 1x2 (100-mil) female capacitive sensor input header, J103, enabling users to connect the provided sensor PCB or their custom sensor designs. A 10 kΩ (0805 size) series resistor (R113) is placed in line with the capacitive sense line to filter out high-frequency noise. The series resistor, in combination with the capacitive sensor, forms an RC circuit. For optimal performance, users must adjust the series resistor value according to the capacitance of their sensor design.
Figure 7-1. Capacitive Sensor Connection

Conductive Sensor Input

The MTCH9010 Evaluation Kit includes a 1x2 (100-mil) female conductive sensor input header, J102, enabling users to connect the provided sensor PCB or their custom sensor designs. To improve performance and reliability of the conductive sense signals, two 10 kΩ (0805 size) pull-up resistors (R111 and R112) are used. These resistors help maintan stable signal levels and minimize noise. For optimal performance, users must adjust the pull-up resistor values according to their sensor design.
Figure 7-2. Conductive Sensor Connection