PT8A2621 Datasheet, PDF (6/13 Pages) Pericom Semiconductor Corporation – PIR Sensor Light Switch Controller

Data Sheet
PT8A2611/2621
PIR Sensor Light Switch Controller
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MODE
MODE is a tri-state input pin for operation mode selection.
See the following table 2.
Override Control (for PT8A2621 only): The term “override”
refers to the change of operating mode by switching the power
switch twice within 3 seconds. When the chip is working in
the AUTO mode (MODE pin openned), the output is activated
by a valid PIR trigger signal and the output active duration is
controlled by the OSCD oscillation period. The lamp can be
switched to ON from the AUTO mode by either switching the
MODE pin to V_CC or switching the power switch twice within 3
Table 2. Operation Modes by MODE Pin
seconds. The device can be toggled from ON to AUTO by
switching the power switch twice within 3 seconds again (over-
ride operation).
If the chip is overridden to ON and there is no further override
operation, it will return to AUTO automatically after an inter-
nal preset ON time duration (8 hours).
Note:Flash is only for the TRIAC Rev.
RST Pin
RST is used to reset the device. It is internal pull-high and
active low. The use of C_RST can extend the power-on initial
time. If the RST pin is openned (without CRST), the initial
time is 40 seconds. See Figure 6.
MODE
Status
V
CC
Operation
Mode
Description
ON
Output is always ON: RELAY pin sends high level for relay driving; TRIAC pulse train output is
synchronized by ZC for triac driving.
GND
Open
OFF
AUTO
Output is always OFF: RELAY pin sends low level for relay driving; TRIAC pin sends high level
for triac driving.
Outputs remain in the OFF state until activated by a valid PIR trigger input signal. When working
in the AUTO mode, the device allows override control by switching the ZC signal.
Figure 5. Override Timing (for PT8A2621)
Operating Mode
AUTO
ON
ZC
AUTO
ON
8 hours
AUTO
Figure 6. RST Application Example
REST
PT0091(04/03)
V _CC
RST
CRST
GND
6
Ver:3