Microchip Technology

The RE46C144 is low power CMOS photoelectric type smoke detector IC. With minimal external components this circuit will provide all the required features for a photoelectric type smoke detector. It has low quiescent current, temporal horn pattern, and can connect up to 40 detectors using the built-in alarm IO.

The RE46C145 is low power CMOS photoelectric type smoke detector IC. With minimal external components this circuit will provide all the required features for a photoelectric type smoke detector. It has low quiescent current, temporal horn pattern, and can connect up to 40 detectors using the built-in alarm IO.

The RE46C152 is a low power CMOS ionization type smoke detector IC. With few external components this circuit will provide all the required features for an ionization type smoke detector. An internal oscillator strobes power to the smoke detection circuitry for 10.5mS every 1.66 seconds to keep standby current to a minimum. A check for a low battery condition is performed every 40 seconds when in standby. The Tone input allows for selection of a temporal pattern or a 2/3 duty cycle continuous tone. The temporal horn pattern supports the NFPA 72 emergency evacuation signal. An interconnect pin allows multiple detectors to be connected such that when one units alarms all units will sound. An internal 8 minute timer allows for a separate button to be used for reduced sensitivity mode. Single button operation for test and timer mode is also possible. Although this device was designed for smoke detection utilizing an ionization chamber it could be used in a variety of security applications.

The RE46C166 device is a low-power, CMOS photoelectric type, smoke detector IC. With minimal external components, this circuit will provide all the required features for a photoelectric type smoke detector. Each design incorporates a gain selectable photo amplifier for use with an infrared emitter/detector pair. An internal oscillator strobes power to the smoke detection circuitry for 100 µs every 10 seconds to keep standby current to a minimum. If smoke is sensed, the detection rate is increased to verify an alarm condition. A high gain mode is available for push button chamber testing. A check for a low battery condition and chamber integrity is performed every 43 seconds when in standby. A continuous tone horn pattern is used for the alarm condition. An interconnect pin allows multiple detectors to be connected so when one unit alarms, all units will sound. A charge dump feature will quickly discharge the interconnect line when exiting a local alarm. An internal 9 minute timer allows for single button, push-to-test to be used for a reduced sensitivity mode. An alarm memory feature allows the user to determine if the unit has previously entered a local alarm condition.

The RE46C180 is a next generation low power programmable CMOS ionization type smoke detector IC. With minimal external components this circuit will provide all the required features for an ionization type smoke detector. An on-chip oscillator strobes power to the smoke detection circuitry for 5ms every 10 seconds to keep standby current to a minimum. A check for a low battery condition is performed every 80 seconds and ionization chamber test is performed once every 320 seconds when in standby. The temporal horn pattern supports the NFPA 72 emergency evacuation signal. An interconnect pin allows multiple detectors to be connected such that when one unit alarms all units will sound. A charge dump feature will quickly discharge the interconnect line when exiting a local alarm. The interconnect input is also digitally filtered. An internal 9 minute or 80s timer can be used for a reduced sensitivity mode. A local alarm memory feature allows the user to determine if the unit has previously entered a local alarm condition.

The RE46C181 is a next generation low power programmable CMOS ionization type smoke detector IC. With minimal external components this circuit will provide all the required features for an ionization type smoke detector. An on-chip oscillator strobes power to the smoke detection circuitry for 5ms every 10 seconds to keep standby current to a minimum. A check for a low battery condition is performed every 80 seconds and ionization chamber test is performed once every 320 seconds when in standby. The temporal horn pattern supports the NFPA 72 emergency evacuation signal. An interconnect pin allows multiple detectors to be connected such that when one unit alarms all units will sound. A charge dump feature will quickly discharge the interconnect line when exiting a local alarm. The interconnect input is also digitally filtered. An internal 9 minute timer can be used for a reduced sensitivity mode. A local alarm memory feature allows the user to determine if the unit has previously entered a local alarm condition. A Chamber Monitor function checks for ionization chamber degradation.

The RE46C182 is a next generation low power programmable CMOS ionization type smoke detector IC. With minimal external components this circuit will provide all the required features for an ionization type smoke detector. An on-chip oscillator strobes power to the smoke detection circuitry for 5ms every 10 seconds to keep standby current to a minimum. A check for a low battery condition is performed every 80 seconds and ionization chamber test is performed once every 320 seconds when in standby. The temporal horn pattern supports the NFPA 72 emergency evacuation signal. An interconnect pin allows multiple detectors to be connected such that when one unit alarms all units will sound. A charge dump feature will quickly discharge the interconnect line when exiting a local alarm. The interconnect input is also digitally filtered. An internal 9 minute timer can be used for a reduced sensitivity mode. A local alarm memory feature allows the user to determine if the unit has previously entered a local alarm condition. A Chamber Monitor function checks for ionization chamber degradation.