Pin count reduction
Instead of a dedicated proximity sensor, a ganged sensor can be tuned as proximity sensor. In an application that uses a small pin packaged device, this approach saves one or more number of pins, depending on the number of proximity sensors in the application.
Increased proximity distance
a) Combining all proximity sensors used for gesture recognition increases the proximity-detection range for detection of an approaching human hand.
b) Combining touch sensors with an existing proximity sensor increases proximity range for a given board size where the proximity sensor size is restricted.
In Part II, we have covered trade-offs between response time and power consumption, as well as other issues resolved by a ganged sensor. In Part III, we will cover sensor ganging implementation and more techniques to optimize power consumption in a ganged sensor application.
To understand more on how to calculate average power consumption for a capacitive sensing controller, refer to AN66308 - CY8CMBR2044 CapSense® Design Guide