RE46C165 Microchip Technology Inc., RE46C165 Datasheet - Page 11

• Manufacturer Part Number: RE46C165
• Description: Cmos Photoelectric Smoke Detector Asic With Interconnect, Timer Mode And Alarm Memory
• Manufacturer: Microchip Technology Inc.

2.0
The descriptions of the pins are listed in
TABLE 2-1:
2.1
The capacitor connected to the C1 pin sets the photo
amplifier gain (high) for the push-to-test and chamber
sensitivity test. The size of this capacitor will depend on
the chamber background reflections. A = 1 + (C1/10),
where C1 is expressed in pF. The gain should be
<10000.
The capacitor connected to the C2 pin sets the photo
amplifier gain (normal) during standby. The value of this
capacitor will depend on the smoke sensitivity required.
A = 1 + (C2/10), where C2 is expressed in pF.
2.2
This input is normally connected to the cathode of an
external photo diode operated at zero bias.
2.3
Regulated output voltage of V
during a test for smoke. This output is the negative side
of the photo amplifier reference circuitry.
 2010 Microchip Technology Inc.
RE46C165/6/7/8
PDIP, SOIC
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13
14
15
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1
2
3
4
5
6
7
8
9
PIN DESCRIPTIONS
High/Normal Gain Capacitor Pins
(C1, C2)
Photo Diode Input (DETECT)
Strobed Detection
Negative Supply (STROBE)
PIN FUNCTION TABLE
STROBE
DETECT
Symbol
COSC
ROSC
FEED
VSEN
TEST
IRED
LED
V
V
HB
HS
C1
C2
IO
DD
SS
DD
– 5, which is active
Table
High Gain Capacitor Pin
Normal Gain Capacitor Pin
Photo Diode Input
Strobed Detection Negative Supply
Positive Power Supply
Infrared Emitting Diode Pin
Interconnect Pin
Horn Brass, Inverted Output
Horn Silver Output
Horn Feedback Pin
LED Driver Pin
Oscillator Capacitor Input
Oscillator Resistor Drive Low
Negative Power Supply
Hush Timer Sensitivity Pin
Test Pin
2-1.
2.4
The V
2.5
Provides a regulated pulsed output voltage pre-driver
for the infrared emitter. This output usually drives the
base of an NPN transistor.
2.6
This bidirectional pin provides the capability to
interconnect many detectors in a single system. This
pin has an internal pull-down device.
2.7
The HB pin is connected to the metal electrode of a
piezoelectric transducer.
2.8
The HS pin is a complementary output to HB and
connects to the ceramic electrode of the piezoelectric
transducer.
DD
Positive Power Supply (V
pin is the device’s positive power supply input.
Infrared Emitting Diode Pin (IRED)
Interconnect Pin (I/O)
Horn Brass, Inverted Output (HB)
Horn Silver Output Pin (HS)
Function
RE46C165/6/7/8
DS22251A-page 11
DD
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