eltrend
WT8076
Passive Infrared (PIR) Controller
Version 1.0 25-May-1995
©Weltrend
Semiconductor, Inc. All Rights Reserved
GENERAL DESCRIPTION
The WT8076 is a PIR controller IC which integrates amplifier, window detector and light control
functions. The light can be controlled by a Relay or Triac with adjustable delay time. A CDS interface is
provided to sense day time and night time. A walk-test fuction helps user while setting up the light set.
The line remote control function can switch the light set between auto mode and always-on mode.
FEATURES
•
Adjustable detection range
•
Adjustable delay time
•
CDS interface to differentiate night time and day time
•
Walk-test function
•
Line remote control to switch auto mode and always on mode
•
Relay or Triac output
•
High noise immunity
•
Low power consumption ( operating 500uA, standby 130uA, Typ. )
PIN ASSIGNMENT
WT8076N16P1
UOU1
NII1
II1
VREF
GND
TB
TCI
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
UOU2
NII2
II2
CDS
VDD
ZCD
RELAY
TRIAC
WT8076S16P1
GND
TB
TCI
TRIAC
RELAY
ZCD
VDD
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VREF
II1
NII1
UOU1
UOU2
NII2
II2
CDS
WT8076N18P2
UOU1
NII1
II1
VREF
GND
TB
TCI
TRIAC
1
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
10
UOU2
NII2
II2
CDS
VDD
ND
WK
ZCD
RELAY
Ordering Information
PART No.
WT8076N16P1
WT8076S16P1
WT8076N18P2
PACKAGE
16 Pin P-DIP
16 Pin SOIC
18 Pin P-DIP
1
Weltrend Semiconductor Inc.
2F, No. 24, Industry E. 9
th
RD., Science-Based Industrial Park, Hsin-Chu, Taiwan
TEL:886-3-5780241 FAX:886-3-5794278.5770419
eltrend
WT8076
Passive Infrared (PIR) Controller
PIN DESCRIPTION
Pin No.
N16P1
S16P1
N18P1
Name
1
2
3
4
5
6
7
8
9
10
11
UOU1
NII1
II1
VREF
GND
TB
---
TCI
TRIAC
RELAY
ZCD
Descriptions
Output of the first stage OP amplifier.
Non-inverting input of the first stage OP amplifier.
Inverting input of the first stage OP amplifier.
Reference voltage output.
Ground.
Time Base. A RC oscillaror is connected on this pin.
Typical frequency is 30kHz.
No connection.
Time control input. A RC oscillator is connected on this
pin. It controls the delay time of the light.
Triac control pin. Active low.
Relay control pin. Active hight.
Zero-crossing input. It detects the zero-crossing point of
the AC line. The ouput of TRIAC pin is synchronous to this
pin.
Walk-Test function enable/disable. Internal pull low. The
walt-test function is disbled when this pin is high level.
Night and day detection enable/disable. Internal pull low.
The night-and-day detection is disbled when this pin is
high level.
Power supply.
Connect a photo-sensitive resistor to detect night time
and day time. If the input level is lower than 1.2V, it is
day time. If the input level is higher than 1.9V, it is night
time.
Inverting input of the second stage OP amplifier.
Non-inverting input of the second stage OP amplifier.
Output of the second stage OP amplifier.
1
2
3
4
5
6
7
8
9
10
11
13
14
15
16
1
2
3
4
5
6
7
*
*
*
*
12
13
WKT
ND
12
13
8
9
14
15
VDD
CDS
14
15
16
10
11
12
16
17
18
II2
NII2
UOU2
* WT8076N16P1 and WT8076S16P1 : Walk-Test and Night&Day function is always enabled.
2
Weltrend Semiconductor Inc.
eltrend
BLOCK DIAGRAM
WT8076
Passive Infrared (PIR) Controller
VDD
WT8076
TB
VDD
ND
VDD
CONTROL
TCI
OSC
Counter
LOGIC
RELAY
CDS
CDS
Window
Detector
TRIAC
ZCD
OSC
System Clock
WKT
1.25V
VREF
REF.
VOLTAGE
1.95V
3.2V
Pulse Width
Detector
PIR
NII1
1.6V
II1
UOU1
NII2
II2
UOU2
WT8076 Block Diagram
3
Weltrend Semiconductor Inc.
eltrend
FUNCTIONAL DESCRIPTION
WT8076
Passive Infrared (PIR) Controller
PIR Amplifier
The amplifier has two stages, please see block diagram . The voltage gain and frequency response can
be adjusted by the external resisters and capacitors.
Window Detector
If the amplified PIR signal is between V
H
(1.95V) and V
L
(1.25V), the signal is ignored and the output of
the window detector is low level. If the amplified signal is larger than V
H
or smaller than V
L
, the output of
the window detector is high level.
Pulse Width Detector
The pulse width detector detects the pulse width of the window detecter's output. If the pulse width is
less than 90ms ( f
TB
= 30kHz ), this pulse is ignored. If the pulse width is larger than 90ms, it will trigger
the light to turn on.
Light Control
The light is controlled by the RELAY pin or TRIAC pin. The RELAY pin outputs a high level when a valid
pulse is detected. The delay time is determined by the RC on the TCI pin. If another valid pulse
occurs during the delay time, the delay time will be reset. Fig. 1 shows the relationships.
The TRIAC pin is an open drain NMOS output. The turn on angle is about 24
O
.
Signal on
UOU2 Pin
1.95V
1.25V
<90ms
>90ms
>90ms
<90ms
>90ms
Window detector
output
Pulse width
detector output
RELAY pin
delay time
90ms
TRIAC pin
ZCD pin
Figure.1 Timing Relationship
4
Weltrend Semiconductor Inc.
eltrend
WT8076
Passive Infrared (PIR) Controller
CDS Interface
The CDS interface detects the level on the CDS pin. If the level is higher than 1.95V, it is night time.
If the level is lower than 1.25V, it is day time.
Operating Modes
The operating modes of WT8076 are:
(1) Auto mode:
The light will turn on when a valid pulse is detected in the night time.
(2) Always on mode:
If the ND pin is low level, the light is always on in the night time. When it detects day time, the
light will be turn off, and back to auto mode.
If the ND pin is high level, the light is always on.
(3) Walk-test mode:
The walk-test mode is active after the power is on. This mode is same as the auto mode except
the CDS is ignored. That is, the light will be turn on when a valid pulse is detected no matter it is
night time or day time.
Remote Control
To switch auto mode between always on mode, the WT8076 detects the zero crossings of the AC line. If
the line switch OFF and ON one time in 3 seconds, it toggles the auto mode and always on mode.
Time Base
The RC oscillator on the TB pin generates the system clock. The frequency is 30kHz typically (R
=30Kohm, C=1000pF) .
The following parameters are decided by the time base :
(1) Trigger angle of the TRIAC (24
O
, if time base is 30kHz).
(2) Pulse width (90ms,if time base is 30kHz).
(3) Remote control switch time.
(4) Disable PIR after the light is off.
(5) Total walk-test time.
The RC oscillator on the TCI pin sets the delay time. Figure 2 shows the relationship betwteen delay
time and the R ( C=1000pF).
5
Weltrend Semiconductor Inc.
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
