Specification

The graph below shows the power consumption for various sensor module's lengths, in active and idle mode. In active mode, the scanning frequency is set to 100 Hz, and one object is presented in active area. In idle mode the scanning frequency is set to 33 Hz, with a clean active area. With higher scanning frequency or more detected objects, the power consumption might be slightly higher than the values in the graph. The sensor module will only be in active mode when a touch object is being detected or tracked.

The power consumption is about the same for USB/HID and I2C. The power consumption will vary with different sensor parameter configurations. The graph above is valid for a default sensor parameter configuration. By increasing the scanning range from default, the power consumption will increase.

Definition

The power consumption is calculated from the current consumption when supplying the sensor module with 5 V. 

The current consumption is, in turn, defined as the average current that goes through a sensor module. This is measured from the +5V power pin and reflects how much electric energy that is consumed by the whole sensor module. In real time, the current is not a stable value. Since the Touch Sensor Module has a low power consumption design, the processor and some peripheral circuits will switch to sleep mode during the time between two scan periods, to save power. Therefore, the current is frequently changing during run time.

According to the different working modes of the Touch Sensor Module, the current consumption value also changes between Active mode and Idle mode.