The Microchip RE46C422 is a low-power smoke detector Analog Front End (AFE) intended for battery-powered applications. The AFE provides all the needed analog, interface and power regulation functions for a microcontroller-(MCU) based multicriteria smoke detector. It can be powered by two AA batteries or a single lithium battery. The RE46C422 features a dual-input integrating photo amplifier to interface with a photoelectric smoke chamber, two independently controlled programmable LED drivers, an analog buffer circuit (ABUF) for monitoring system voltages, a four terminal CO monitor, and a 3.3V regulator. The RE46C422 is capable of meeting UL 217 9th Ed and UL 268 7th Ed specifications and can be easily adapted to new editions with its programmable design and rich feature set. For designs that do not require two integrating photo amplifiers, see the RE46C420. For designs that do not require CO monitoring, see the RE46C421.
Product Features
Low Quiescent Current
Operation from Two AA Batteries, Single Lithium Battery or 9V Battery
4V, 8.5V, 10V, 11.5V, 17V Boost Converter
3.3V Regulator
Piezoelectric Horn Driver
Dual Independently Controlled LED Drivers with Programmable Current up to 200 mA
Dual-Input Programmable Gain Integrating Op Amp with Effective Transimpedance > 20 M at 100 μs
CO & Toxic Gas Monitoring
Analog Buffer for Sensing Multiple Internal Voltages (ABUF)
Alarm Interconnect
SPI Controlled