Description

The Microchip RE46C400/1 is a low-power smoke

detector MCU companion IC intended for panel-based

applications. It provides all of the analog, interface and

power regulation functions for a microcontroller-(MCU)

based multicriteria smoke detector. The RE46C400/1

can be powered from a constant current typically used

in panel-based applications. The product features an

integrating photo amplifier to interface with a

photoelectric smoke chamber, two independently

controlled programmable LED drivers, an op amp with

10 kHz Gain Bandwidth Product and rail-to-rail inputs

and output to interface with a two terminal CO sensor,

an analog buffer circuit (ABUF) for monitoring system

voltages and a 3.3V regulator. The RE46C401 does not

include the CO circuitry.

The RE46C400/1 allows the MCU to control all the

parameters which set the operating conditions of the

RE46C400/1 such as LED current, amplifier gain and

integration time. All of these parameters including the

enabling of various functions will be set via the SPI port.

Features

• Low Quiescent Current

• 3.3V Regulator

• Dual Independently Controlled LED Drivers with

Programmable Current up to 200 mA

• Single Programmable Gain Integrating Op Amp

with Effective Transimpedance > 20 M at 100 μs

• Internal Op Amp for use with CO or Toxic Gas Sensor

- Rail-to-Rail Inputs and Output

- Unity Gain Stable

- 10 kHz Gain Bandwidth Product

• Buffered Internal CO reference

• Voltage Monitoring Circuit (ABUF)

• Watchdog Timer

• SPI Controlled

• Powered from a Current Source