www.DataSheet4U.com CS4121 Low Voltage Precision Air Core Tach/Speedo Driver The CS4121 is specifically designed for use with air core meter movements.
The IC provides all the functions necessary for an analog tachometer or speedometer.
The CS4121 takes a speed sensor input and generates sine and cosine related output signals to differentially drive an air core meter.
Many enhancements have been added over industry standard tachometer drivers such as the CS289 or LM1819.