RE46C152

CMOS Ionization Smoke Detector ASIC with Interconnect,

R&E International

Timer Mode and Tone Select

A Subsidiary of Microchip Technology Inc.

Product Specification

© 2009 Microchip Technology Inc.

DS22175A-page 8

Typical Application – 1 Button Operation, Temporal Horn Pattern

Figure 3

Notes for Application Drawing Figure 3:

Select R5 and R6 values for the correct level to test the ion chamber. The voltage level at the TSTART input (pin 1) must be

greater than the minimum VIH level to initiate the timer mode. Pin 1 has an internal 180K nominal pull down which must be

considered.

Select R9 to reduce sensitivity during the timer mode.

R3, R4 and C1 are typical values and may be adjusted to maximize sound pressure.

C2 should be located as close as possible to the device power pins.

Route the pin 8 PC board trace away from pin 7 to avoid coupling.

If used R10 is 1.5K minimum