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Datasheets:
A5303: Photoelectric Smoke Detector with Interconnect, Timer, and Latching Alarm Indicator (PDF)
Selection Guides:
Power Integrated Circuits,
Smoke Detector ICs
Press Releases:
A5303: Allegro MicroSystems, Inc. Introduces New Standard 3 V Smoke Detector,
A5303: Netzwerkfähiger Rauchmelde-IC mit extrem geringer Stromaufnahme,
A5303: Circuit intégré détecteur de fumée, très faible consommation, pouvant être mis en réseau
The A5303 is a low-current BiCMOS photoelectric smoke detector circuit with ultra-low standby current and can operate for 10 years powered by inexpensive batteries. This device can be used with an infrared optical chamber to sense light scattered from smoke particles. A networking capability allows units to be interconnected so that if any unit senses smoke all units will sound an alarm. Special features are incorporated in the design to facilitate calibration and testing of the finished detector.
A variable-gain photoamplifier can be directly interfaced to an infrared emitter-detector pair. The amplifier gain levels are determined by two external capacitors and are internally selected depending on the operating mode. Low gain is selected during standby and timer modes. During a local alarm, this low gain is increased (internally) by approximately 45% to provide hysteresis. High gain is used during pushbutton test and to periodically monitor the chamber sensitivity during standby. The internal oscillator and timing circuitry minimize standby power by sensing for smoke for only 100 µs once every 10 s. A special three-stage-speedup sensing scheme is incorporated to minimize the time to an audible alarm and also to reduce false triggering. Chamber sensitivity is periodically monitored and two consecutive cycles of degraded sensitivity are required for a warning signal to occur.
The A5303 is supplied in a thin profile (<1.2 mm overall height) 20-pin TSSOP package (0.65 mm nominal lead pitch). The package is lead (Pb) free with 100% matte tin leadframe plating.
| Part Number | Package Type | RoHS Compliant |
Part Composition/ RoHS Data |
Temperature | Comments | Samples | Distributor Stock |
|---|---|---|---|---|---|---|---|
| A5303SLE-T | 20-lead TSSOP | Yes | view data | -20 °C to 85 °C | new |
Contact Local Sales Representative or check distributor stock |
|
| A5303SLETR-T | 20-lead TSSOP | Yes | view data | -20 °C to 85 °C | new |
Contact Local Sales Representative or check distributor stock |
Allegro's products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system.