Microchip公司的RE46C19是CMOS低压光电烟雾检测ASIC，符合标准UL217和 UL268，集成了可选增益的光放大器. RE46C19每10秒检测烟雾一次，如果检测到烟雾，将会发出告警信号.两节干电池工作，器件内部有红外二极管(IRED)驱动器，可调整IRED驱动电流以及静态灵敏度.本文介绍了RE46C190主要特性，方框图， 电池应用电路图以及用于编程的应用电路图.

 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