The WS2418 is a monolithic integrated circuit telephone tone ringer with bridge diode, when coupled with an appropriate transducer, it replaces the electromechanical bell. This device is designed for use with either a piezo transducer or an inexpensive transformer coupled speaker to produce a pleasing tone composed of a high frequency (fR) alternating with a low frequency (fL) resulting in a warble frequency. The supply voltage is obtained from the AC ring signal and the circuit is designed so that noise on the line or variation of the ringing signal cannot affect correct operating of the device.

FEATURES
 On chip high voltage full wave diode bridge rectifier
 Low current consumption, in order to allow the parallel operation of the 4device
 Low external component count
 Tone and switching frequencies adjustable by external components
 High noise immunity due to built-in voltage current hysteresis
 Activation voltage adjustable
 Internal zener diodes to protect against over voltages
 Ringer impedance adjustable with external components
 Electronic telephone ringers
 Extension ringers