The MC14568, when used with an ionization chamber and a small number of external components, will detect smoke. When smoke is sensed, an alarm is sounded via an external piezoelectric transducer and internal drivers. This circuit is designed to operate in smoke detector systems that comply with UL217 and UL268 specifications.

FEATUREs
• Speed-Up Sampling Rate of 40 ms of Internal Clock Period (Pin 12) After First Detection of Smoke
• Timer Function for Reduced Sensitivity for a Nominal Period of 6.43 Minutes (10 Minutes Max)
• High-Smoke Detection in the “Reduced Sensitivity” Mode
• Internal and External Low Battery Threshold
• Internal and External Smoke Reference Settings
• Guaranteed Power Up Without Random LED and Horn Chirps
• Reversed Battery Protection
• Low Leakage Detect Pin
• Metal Option to Add Double Chirp atEnd of Reduced Sensitivity Period; Default is No Chirp
• Pb-Free Packaging Designated by Suffix Code ED