pt8a2620 Pericom Technology Inc, pt8a2620 Datasheet - Page 3

• Manufacturer Part Number: pt8a2620
• Description: Pir Sensor Light Switch Controller
• Manufacturer: Pericom Technology Inc

PT0119(03/03)
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Functional description
Pulse width detection (PWD) or Noise rejection circuit
Pulse width detection can be used to filter the noise in order to
prevent error trigger from the system. The default criteria of
the width must be more than 400ms which can be set with an
external RC.
Hold time (HT)
Hold time, in other word, the output active duration, it can be
set with an external RC. One various resistor can be used to
changed the related output duration.
Force on function
The IC can force the controlled lamp to on state by turning off
the power supply for a brief period of time. During this brief
power interruption, the power to the IC must be maintained.
Shown in the schematic, with ON input discharged to low
while RST maintains at high, the lamp output can be set to on
until a RST input is low (longer period of power down). This
feature may cause not intended lamp on situation during brief
power interruption. Tie ON to V
Trigger Timing
RELAY
Comparator
Comparator
PWD
POR
ON
HT
CDS
RST
Output
Input
CC
power on reset
to disable this feature.
time 40s
An active pulse width
Hold
time
3
Power on Reset (POR)
The external PIR sensor requires a period of up to 40 seconds
to stabilize, so a power on reset circuit is required to ensure
proper operations. During this power on reset period, the lamp
is on to indicate proper operation.
Retrigger
If another PIR signal is attained with valid duration, the circuit
will be retriggered, and the hold time will be restarted from
this time.
Force On Function
PIR Sensor Light Switch Controller
PT8A2620
+trigger level
Threshold
Threshold
Threshold
-trigger level
POR
Data Sheet
PT8A2620
RST
ON
Ver:2