GENERAL DESCRIPTION

The M75210 is a very low-power IC providing all of the required features for a photoelectric type smoke detector. It is

designed for operate at supply voltage as low as 2.7V and suited to 3V Lithium battery powered application. A variable-gain

photo amplifier can be directly interfaced to an infrared emitter / detector pair. The amplifier gain levels are determined by

two external capacitors that are then internally selected depending on the operating mode. Low gain is selected during standby.

During a local alarm this low gain is increased (internally) by ~ 10 to reduce false triggering. High gain is used during the

push-button test and during standby to periodically monitor the chamber sensitivity. The internal oscillator and timing

circuitry keeps standby power to a minimum by sensing for smoke every 10 seconds in a 100 μs window.

FEATURES

? Operating voltage range 2.7V ~ 5V

? Local or Remote Smoke Alarm output.

? Low-Battery Trip Point Set Externally

? Power-on Reset.

? Built-in circuits to reduce false triggering.

? Average Supply Current: 4μA @VDD=3.0V

? ESD-Protection circuitry on all pins.

APPLICATIONS

? Smoke detector.