5 Status LEDs

The MTCH9010 Evaluation Kit uses two LEDs to indicate liquid detection and the heartbeat. Both statuses are digital signals with an active high logic. The liquid-detected LED will shine when the MTCH9010 detects liquid exceeding the configured threshold.

The heartbeat output indicates that the device is functioning correctly. The heartbeat signal depends on the configured Sleep period, the output level toggling every time the device enters the Sleep state. See the MTCH9010 data sheet for more information on the heartbeat feature.

Important: The MTCH9010 will indicate an error state using the output and heartbeat signals, causing the liquid detect and heartbeat LEDs to blink. See the MTCH9010 data sheet for more information on error codes.
Figure 5-1. Status LEDs Overview

MOSFET switches are used to separate the current draw of the LEDs from the MTCH9010. The pull-down resistors for the MOSFET gates are selected to have a minimal effect on the total current drawn by the MTCH9010.