Description

The A5348 is a low-current, BiCMOS circuit providing all of the required features for an ionization-type smoke detector. A networking capability allows as many as 125 units to be interconnected so that if any unit senses smoke all units will sound their alarm. In addition, special features are incorporated to facilitate alignment and test of the finished smoke detector.

The internal oscillator and timing circuitry keep standby power to a minimum by powering down the device for 1.66 seconds and sensing for smoke for only 10 ms. Every 24 on-off cycles, a check is made for a low battery condition. By substituting other types of sensors or a switch for the ionization detector, this very-low–power device can be used in numerous other battery-operated safety/security applications.

Features and Benefits

▪ Low average standby current for long battery life

▪ Interconnect up to 125 detectors

▪ Piezoelectric horn driver

▪ Guard outputs for detector input

▪ Pulse testing for low battery

▪ Power-on reset (POR)

▪ Internal reverse battery protection

▪ Timer (Hush) mode for enabling reduced sensitivity period

▪ Built-in hysteresis reduces false triggering