6.4.3 Wake-up-on-Approach Mode

The Wake-up-on-Approach mode is a low-power mode allowing an autonomous wake-up of the MGC3140 and application host. In this mode, the MGC3140 is automatically and periodically alternating between Deep Sleep and scan phases.

During the approach scan phase, the sensor will be able to detect an approach of the human hand and change to Processing mode accordingly.

The MGC3140’s fast wake-up, typically below 1 ms, allows the performance of scans in very efficient periods and to maximize the Sleep phase.

Additionally, the sensor will perform periodic AFA scans in which the sensor will scan through all available Tx frequencies and select an optimal frequency depending on the signals’ noise level.

The periodic wake-up sequence is triggered by a programmable wake-up timer running at the low-speed Oscillator 32 kHz frequency. The repetition rate of the scan can be adjusted via the host, affecting the sensitivity and current consumption during Wake-up-on-Approach.

The MGC3140 enters the Self Wake-up mode by a GestIC Library message or by a non-activity time-out. Non-activity means no user detection within the sensing area.