The RE46C190 is not recommended for new designs.Please use the RE46C191 for all new designs.The RE46C190 is a low voltage, low current programmable photoelectric smoke detector IC. This circuit will provide all the required features for a photoelectric smoke detector with minimal external components. Programmable setup, calibration and feature selection are the key to reduced component count and reduced manufacturing costs. The boost regulator insures proper operation of the infrared diode and the piezo hor