RE46C122

CMOS Ionization Smoke Detector ASIC with

R&E International

Interconnect and Timer Mode

A Subsidiary of Microchip Technology Inc.

Product Specification

© 2009 Microchip Technology Inc.

DS22173A-page 8

Timing Diagram (non Timer Mode)

Standby Mode; No Low Battery; No Alarm

Alarm; No Low Battery

Alarm; Low Battery

Oscillator

1.67S

10.5mS

Internal Clock

24 Clock Cycles (40 S)

LED

Sample Smoke

Low Battery Warning Chirp

Horn

See Figure Below for Complete Horn Cycle

IO (Pin 2) as Output

Timing not same scale as above

IO Charge Dump

IO ( Pin 2) as Input

LED supressed in remote alarm mode

Horn

Start of horn temporal pattern is not synchronized to an external alarm

Horn pattern not self completing for external alarm,see timing below for complete horn cycle

Internal Clock

Notes:

1. Smoke is not sampled when the horn is active. Horn cycle is self completing in local alarm.

2. Low battery warning chirp is suppressed in local or remote alarm

3. IO Dump active only in local alarm, inactive if external alarm

Complete Temporal Horn Pattern

Pin 15 > Pin 13

Pin 15 > Pin 13

Pin 13 > Pin 15; 130mV Level Shift on Pin 13

No Alarm; Low Battery

24 Clock Cycles (1S)