Microchip公司的RE46C19是CMOS低壓光電煙霧檢測ASIC,符合標準UL217和 UL268,集成了可選增益的光放大器. RE46C19每10秒檢測煙霧一次,如果檢測到煙霧,將會發出告警信號.兩節干電池工作,器件內部有紅外二極管(IRED)驅動器,可調整IRED驅動電流以及靜態靈敏度.本文介紹了RE46C190主要特性,方框圖, 電池應用電路圖以及用于編程的應用電路圖.
The RE46C190 is a low power, low voltage CMOS photoelectric type smoke detector IC. With minimal external components, this circuit will provide all the required features for a photoelectric-type smoke detector.
The 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 every 10 seconds, to keep the 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 is performed every 86 seconds, and chamber integrity is tested once every 43 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.
An internal 9 minute timer can be used for a Reduced Sensitivity mode.
Utilizing low power CMOS technology, the RE46C190 was designed for use in smoke detectors that comply with Underwriters Laboratory Specification UL217 and UL268.
RE46C190主要特性:
• Two AA Battery Operation
• Internal Power On Reset
• Low Quiescent Current Consumption
• Available in 16L N SOIC
• Local Alarm Memory
• Interconnect up to 40 Detectors
• 9 Minute Timer for Sensitivity Control
• Temporal or Continuous Horn Pattern
• Internal Low Battery and Chamber Test
• All Internal Oscillator
• Internal Infrared Emitter Diode (IRED) driver
• Adjustable IRED Drive current
• Adjustable Hush Sensitivity
• 2% Low Battery Set Point
圖1.RE46C190方框圖
圖2.RE46C190電池應用電路圖
圖3.RE46C190用于編程的應用電路圖(1)
圖4.RE46C190用于編程的應用電路圖(2) |
