WT8072
PIR CONTROLLER
Weltrend Semiconductor, Inc.
Page 2
GENERAL DESCRIPTION
WT 8072 is a PIR (passive infra-red) controller, using analog mixing digital design technique and
manufactures by CMOS process which can either drive TRIAC or RELAY depending on users' choice.
With special noise immunity technique, WT8072 is the most stable PIR controller you can find on the
market. More than this, there are few components needed in its application circuit which can reduce
material cost and increase competitive.
FEATURES
*HIGH NOISE IMMUNITY.
*DRIVE EITHER RELAY OR TRIAC.
*ADJUSTABLE LIGHT ON DURATION.
*TRIAC CAN BE EITHER SHUNT OR SERIAL CONNECTED.
*PIR INPUT.
*CDS INPUT.
PIN CONFIGURATION
PIN DESCRIPTION
Pin No. Pin Name I/O
Description
1
UOU1
First stage OP amp output
2
NII 1
First stage OP amp positive input
3
II 1
First stage OP amp negative input
4
VREF
Stable reference voltage
5
GND
System ground
6
TB
Time base for 1. The delay time of receiving PIR singnal to sent a puls to
trigger TRIAC or a high signal to trigger relay.
The delay time = R x C x 32.
The PIR signal patented and accepted only if the signal cycle greater than R
x C x 768 .When state of relay or TRIAC is changing form active into
inactive mode. It takes more than R x C x 4069, then system is able to
receive PIR signal again.
2.The flash cycle show the beginning of auto mode.
Note: Width of TRIAC pulse = R x C x 2.
Flash cycle: R x C x 32768
10 K < R < 1M Ohm
100pF < C < 0.1 Uf (Reference Diagram 1)
7
QTEST
For testing only
WT8072
PIR CONTROLLER
Weltrend Semiconductor, Inc.
Page 3
8
TCI
To set up the timing of how long Triac or relay is active.
During the period, if the system receives the PIR signal, then it restarts
counting the timing again.
The range for R: 10K < R < 1M Ohm
C: 100uF< C < 0.1 uF (Reference Diagram 2)
9
CDS
Connected to a CDS for inhibiting relay or TRIAC being triggered.
If TRIAC or relay has already being triggered by PIR signal and turned into
active mode, then CDS can not inhibit PIR again.
10
TRIAC
To trigger TRIAC, active low
Sink current: 15 mA max.
11
RELAY
To drive relay, active high
Sink current: 10 mA max.
Source current: 10 mA max.
12
ZCD
Detect zero cross of AC line under remote mode function.
13
VDD
Operation voltage: 5V, stand by current: 1mA
14
II2
2
nd
stage OP amp negative input
15
NII2
2
nd
stage OP amp positive input
16
UOU2
2
nd
stage OP amp output
DIAGRAM 1, 2
WT8072
PIR CONTROLLER
Weltrend Semiconductor, Inc.
Page 4
Absolute Maximum Ratings
Parameter
SYMBOL
VALUE
Units
POWER SUPPLY Vdd WITH REPECT TO Vss
Vdd-Vss
5.6
V
VOLTAGE ON ANY PIN
-0.3-5.6
V
OPERATING TEMPERATURE
Top
0-70
C
STORAGE TEMPERATURE
-65-150
C
ELECTRICAL CHARACTERISTICS
Symbol
Parameter
Condition
Min.
Typ.
Max.
Unit
Vdd
SUPPLY VOLTAGE
4.2
5
5.5
V
Ist
STANDY CURRENT
0.9
1.0
1.2
mA
Idd
OPERATING CURRENT
1.8mA, TRIAC
2.5mA, RELAY
1.8
2.5
mA
Vref
STABLE VOLTAGE
Vdd>4.2V
3.0
3.2
3.4
V
Iref
SOURCE CURRENT OF Vref
200
uA
RIPPLE OF Vref
0.5
mV
INPUT AND OUTPUT
REGULATION OF Vref
0.3%
Ftb
TIME BASE OPERATING
FREQUENCY
15
16
17
KHZ
Vt+
CDS OPERATING TRIGGER
1.3
1.7
2.1
V
Vt-
CDS OPREATING TRIGGER
0.6
0.9
1.1
V
Icds
CDS SOURCE CURRENT
2.6
3.5
4.4
uA
Isource CDS OUTPUT SOURCE
CURRENT
9
10.4
17.4
mA
Isink
CDS OUTPUT SINK CURRENT
11.6
13
21
mA
Tout1
TIMER DURATION OF OUT 1
C=0.001uF
R=4.7K-1M
C=0.01uF
R=4.7K-1M
C=100uF
R=4.7K-1M
C=0.1uF
R=4.7K-1M
0.03
4.6
0.08
37.8
9.3
1290
14.9
11170
Sec.
Irs
RELAY SOURCE CURRENT
5
mA
Irsink
RELAY SINK CURRENT
5
mA
Vro
RELAY OPERATING VOLTAGE
18.8V: RELAY ON
13.1V: RELAY OFF
13.1
18.8
V
Itsink
TRIAC SINK CURRENT
15
mA
Itsource TRIAC SOURCE CURRENT
50
uA
WT8072
PIR CONTROLLER
Weltrend Semiconductor, Inc.
Page 5
TYPICAL APPLICATION
HOME SECURITY SYSTEM.
AUTO LIGHT SYSTEM FOR GARDEN, GARAGE, HALLWAY, STAIRCASE, PORCH, BATHROM, AND
ETC.
AUTO SWITCH FOR VENTILATION FAN.
AUTO NOTICE SYSTEM FOR OFFICE, STORAGE, AND ETC.
ORDERING INFORMATION
Ordering Number
Package Type
WT8072
P-DIP 16L
WT8072H
CHIP FORM
WT8072
PIR CONTROLLER
Weltrend Semiconductor, Inc.
Page 6
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