PT8A263 Datasheet, PDF (6/11 Pages) Pericom Semiconductor Corporation – PIR Alarm Controller

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PT8A263
PIR Alarm Controller
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Functional Description
The PIR sensor detects infrared power variations
 Low Battery Detection
induced by the motion of a human body and converts it
Internal low Battery Detector indicates voltage value of
to voltage variations. This input voltage is fed into
PT8A263 for signal processing. Bandpass filtering is
first accomplished by a 2-stage op-amp, followed by
the peak and valley voltages comparisons. If the input
signal is larger than the specified peak voltage or
smaller than the specified valley voltage for a certain
period of time, this PIR trigger signal will be produced
VCC less than a contain value which is about 3.8V. A
Low Battery alarm indication can be given at LED pin
when the division voltage is less than VEE/2. At the
same time the system will be halt. Most of the internal
circuits are hung up except oscillator and LED
indication circuit.
to the internal noise rejection circuit in which a valid
trigger is qualified based on some criteria. The output
signals will then be generated to drive external devices
according to different mode of operations.
 RST
RST is used to reset the chip. It is internal pull-high
and active low. The use of CRST can extend the
power-on initial time. If the RST pin is an open circuit
 V_EE
VEE supplies power to the analog front-end circuit
with a stabilized voltage that is 3.6V with respect to
GND normally.
(without CRST), the initial time is the default (40
seconds).
 Power On Initial
The PIR signal amplifier requires a warm up period
 OSC
after power-on. The input should be disabled during
OSC is an I/O pin of internal oscillator. System
this period.
frequency of 16KHz can be generated when connected
to an external RC.
 Operational Mode
The operation modes of PT8A263 are shown in the
following table.
Mode of Operation/2
SEL1 SEL2
Functions
Normal Alarm: OUT1 = low (active) for 5 seconds after the first trigger. OUT2 goes low for 5 seconds after the
1
1
2nd trigger. LED does not latch trigger status. OUT2 (low active) will not trigger if there is no PIR signal 12
seconds after the first trigger.
Normal Alarm with Delay: OUT1 goes low after first triggered, if the second trigger signal comes after 15
0
1
seconds, OUT2 keep high, if the second trigger signal comes after 12 seconds but less than 15 seconds, OUT2
will goes low for 5 seconds. LED is latched on until power down or reset the chip.
Siren Alarm: Complimentary drive high pitch piezo buzzer. Center frequency = 1kHz (options for 500Hz and
2kHz).
1
0
2 stages of alarm: First trigger: Output is 1/4 sec on, 4 sec off. If no 2nd trigger within 12 sec, all outputs are
reset, no sound. 2nd trigger: Output is 1/4 sec on, 2 sec off for 30 sec. After 30 sec, output = 1 sec on, 1/2 sec off,
continue for 5 minutes. After that, the chip enters stop mode. LED is latched on after 2nd trigger, until power
down or chip reset.
0
0
Door Chime mode: Once trigger occurs, OUT1 is active (high) for 1 sec, OUT2 is active (high) for another 1
sec after OUT1 is asserted. LED has no latch function.
12-07-0006
PT0084-6
07/06/12/12
6