M75012 Datasheet, PDF (2/10 Pages) List of Unclassifed Manufacturers – PHOTOELECTRIC SMOKE DETECTOR WITH INTERCONNECT

一華半導體股份有限公司
MOSDESIGN SEMICONDUCTOR CORP.
PHOTOELECTRIC SMOKE DETECTOR
WITH INTERCONNECT
SMOKE DETECTOR
M75012
ABSOLUTE MAXIMUM RATING
Parameter
Sym.
Rating
Unit
Supply Voltage Range
V_DD
-0.5 ~ 13
V
Input Voltage Range
V_IN
-0.3 to V_DD + 0.3
V
Input Current
I_IN
10
mA
Operating Temperature Range
T_A
-25 ~ 75
℃
Storage Temperature Range
T_S
-55 to 125
℃
PIN AND CIRCUIT DESCRIPTION
Pin No Pin Name
Description
A capacitor connected to this pin determines the gain of the photo amplifier during the push-to-test mode
and during the chamber monitor test. A typical value for this high-gain mode is 0.047μF but should be
1
C1
selected based on the photo chamber background reflections reaching the detector and the desired level of
sensitivity. Ae ≒ 1 + ( C1 / 10 ) where C1 is in pF. Ae should not exceed 10,000.
A capacitor connected to this pin determines the gain of the photo amplifier during standby. A typical value
2
C2
for this low-gain mode is 4700 pF but should be selected based on a specific photo chamber and the
desired level of sensitivity to smoke. Ae ≒ 1 + ( C2 / 10 ) where C2 is in pF. Ae should not exceed
10,000.
3
DETECT
This is the input to the photo amplifier and is connected to the cathode of the photo diode. The photo diode
is operated at zero bias and should have low darkleakage current and low capacitance.
4
STROBE
This output provides a strobed , regulated voltage of VDD-5V. The minus side of all internal and external
photo amplifier circuitry is referenced to this pin.
5
VDD
This pin is connected to the most-positive supply potential and can range from 6V to 12V with respect to
VSS.
This output provides a pulsed base current for the external NPN transistor , which drives the IR emitter. Its
6
IRED beta should be greater than 100. The IRED output is not active , to minimize noise impact , when the horn
and visible LED outputs are active.
A connection at this pin allows multiple smoke detectors to be interconnected. If a local smoke condition
occurs , this pin is driven high. As an input , this pin is sampled nominally every 1.35 seconds during
standby. Any local-alarm condition causes this pin to be ignored as an input.
7
I/O _{An internal NMOS device acts as a charge dump to aid in applications involving a large ( distributed )}
capacitance. The charge dump is activated at the end of local or test alarm. This pin also has an on-chip
pull-down resistor and must be left unconnected if not used. In application , there is a series current-
limiting resistor to other smoke alarms.
8
HORN1
These three pins are used in conjunction with external passive components and a self-resonating
piezoelectric transducer. HORN1 is connected to the piezo metal support electrode ; the complementary
output , HORN2 , is connected to the ceramic electrode and the FEEDBACK input to the feedback
9
HORN2 ^electrode.
A continuous modulated tone indicates either a local or remote alarm condition. A short ( 10ms ) chirp
10
FEEDBACK
indicates a low-battery chirp occurs almost simultaneous
pin is not used , it must be connected to VDD or VSS.
with the
visible
LED flash.
If
the
FEEDBACK
2/10
2006-10-05