Found in Motorola documentation from the 90's, this circuit has a high input impedance. The power supply must be symmetrical. The circuit can be implemented with modern operational amplifiers.
These circuits were found in Exar documentation from the 90s. The circuits use both a small...
The presented circuit is suggested by Texas Instruments (www.ti.com) in its Application Report...
April 2017 - Mouser Electronics already stocks the new Broadcom APDS-9500 proximity and gesture...