Holtek HT761X General purpose pir controller Datasheet

HT761X
General Purpose PIR Controller
Features
•
•
•
•
•
•
•
•
Stand-by current: 100µA (Typ.)
On-chip regulator
Adjustable output duration
CDS input
40 second warm-up
ON/AUTO/OFF selectable by MODE pin
•
•
Override function
Auto-reset if the ZC signal disappears over
3 seconds
Operating voltage: 5V~12V
16 pin DIP or SOP packaging
•
•
Alarm systems
Auto door bells
Applications
•
•
PIR light controllers
Motion detectors
General Description
PIR output voltage variation conforms to the
criteria (refer to the functional description), the
lamp is turned on with an adjustable duration.
The HT761X is a CMOS LSI chip designed for
use in automatic PIR lamp control. It can operate with a 2-wire configuration for triac applications or with a 3-wire configuration for relay
applications. The chip is equipped with operational amplifiers, a comparator, timer, a zero
crossing detector, control circuit, a voltage regulator, a system oscillator, and an output timing
oscillator.
The HT761X offers three operating modes (ON,
AUTO, OFF) which can be set through the
MODE pin. While the chip is working in the
AUTO mode the user can override it and switch
to the TEST mode, or manual ON mode, or
return to the AUTO mode by switching the
power switch. The chip is enclosed in a 16 pin
DIP/SOP.
Its PIR sensor detects infrared power variations induced by the motion of a human body
and transforms it to a voltage variation. If the
Selection Table
Part Number
ZC off/on for
override
Flash on
mode autochange
Override ON
duration
HT7610
2 times
Flash
8 hrs
1
(VDD-VEE)
16
>24ms
HT7611
1 time
No flash
8 hrs
1
(VDD-VEE)
16
>24ms
1
Comparator
Effective
window
trigger width
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HT761X
Pin Assignment
Block Diagram
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HT761X
Pin Description
Pin No.
I/O
Internal
Connection
VSS
I
—
RELAY
O
CMOS
RELAY drive output through an external NPN
transistor, active high
2
TRIAC
O
CMOS
TRIAC drive output
The output is a pulse output when active.
3
OSCD
I/O
PMOS IN
NMOS OUT
Output timing oscillator I/O
It is connected to an external RC to adjust output
duration.
I/O
PMOS IN
NMOS OUT
System oscillator I/O
OSCS is connected to an external RC to set the
system frequency. The system frequency ≅ 16KHz
for normal application.
I
CMOS
Input for AC zero crossing detection
CMOS
CDS is connected to a CDS voltage divider for
daytime/night auto-detection. Low input to this pin
can disable the PIR input. CDS a schmitt trigger
input with 5-second input debounce time.
Operating mode selection input:
VDD: Output is always ON
VSS: Output is always OFF
Open: Auto detection
A
B
1
1
2
3
Pin Name
4
4
OSCS
5
5
ZC
6
6
CDS
I
Description
Negative power supply
7
7
MODE
I
CMOS
8
8
VDD
I
—
9
9
VEE
O
NMOS
10
10
RSTB
I
Pull-High
Chip reset input, active low
11
11
OP1P
I
PMOS
Noninverting input of OP1
12
12
OP1N
I
PMOS
Inverting input of OP1
13
13
OP1O
O
NMOS
Output of OP1
14
14
OP2P
I
PMOS
Noninverting input of OP2
15
15
OP2N
I
PMOS
Inverting input of OP2
16
16
OP2O
O
NMOS
Output of OP2
Positive power supply
Regulated voltage output
The output voltage is about –4V with respect to
VDD.
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24th Mar ’97
HT761X
Absolute Maximum Ratings
Supply Voltage ............................... –0.3V to 13V
Operating Temperature............... –25°C to 75°C
Input Voltage................. VSS–0.3V to VDD+0.3V
Zero Crossing Current.....................max. 300µA
Storage Temperature................. –50°C to 125°C
Electrical Characteristics
Symbol
Test Condition
Parameter
VDD
Condition
—
—
Min.
Typ.
Max.
Unit
5
9
12
V
VDD
Operating Voltage
VEE
Regulator Output Voltage
12V
VDD–VEE
3.5
4
4.5
V
IDD
Operating Current
12V
No load, OSC on
—
100
350
µA
VTH1
CDS “H” Transfer Voltage
12V
—
6.4
8
9.6
V
VTL1
CDS “L” Transfer Voltage
12V
—
3.7
4.7
5.6
V
IOH1
OUTPUT Source Current
(RELAY, TRIAC)
12V
VOH=10.8V
–6
–12
—
mA
IOL1
OUTPUT Sink Current
(RELAY, TRIAC)
12V
VOL=1.2V
40
80
—
mA
IOL2
VEE Sink Current
12V
VDD–VEE=4V
—
1
—
mA
VIH
“H” Input Voltage
—
—
0.8VDD
—
—
V
VIL
“L” Input Voltage
—
—
—
—
0.2VDD
V
VTH2
ZC “H” Transfer Voltage
12V
—
4.7
6.7
8.7
V
VTL2
ZC “L” Transfer Voltage
12V
—
1.3
1.8
2.3
V
FSYS
System Oscillator Frequency
12V
ROSCS=560K
COSCS=100P
12.8
16
19.2
KHz
Fd
Delay Oscillator Frequency
12V
ROSCD=560K
COSCD=100P
12.8
16
19.2
KHz
AVO
OP Amp Open Loop Gain
12V
No load
60
80
—
dB
VOS
OP Amp Input Offset Voltage
12V
No load
—
10
35
mV
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HT761X
Trigger Timing
Note: 1. The output is activated if the trigger signal conforms to the following criteria:
• More then 3 triggers within 2 seconds.
• A trigger signal sustain duration ≥ 0.34 secs.
• 2 trigger signals within 2 secs with one of the trigger signal sustain ≥ 0.16 secs.
2. The effective comparator output width can be selected to be 24ms or 32ms or
48ms by mask option. The default is 24ms (system frequency=16KHz).
3. The output duration is set by an external RC that is connected to the OSCD pin.
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HT761X
Functional Description
VEE
RELAY (TRIAC)
VEE supplies power to the analog front end
circuit with a stabilized voltage which is –4V
with respect to VDD normally.
RELAY is an output pin set as a RELAY driving
(active high) output for the HT761XA, or as a
TRIAC driving (active low) output for the
HT761XB.
OSCS
The output active duration is controlled by the
OSCD oscillating period.
OSCS is a system oscillator input pin. When it
is connected to an external RC a system frequency of 16KHz can be generated.
OUTPUT
HT761XA
HT761XB
RELAY
TRIAC
CDS
CDS is a CMOS schmitt trigger input structure.
It is used to distinguish between day time and
night time. When the input voltage of CDS is
high the PIR input is enabled. On the other
hand, when CDS is low the PIR input is disabled. The input disable to enable debounce
time is 5 seconds. Connect this pin to VDD
when not using this function. The CDS input is
ignored when the output is active.
Fig.1 System oscillator
OSCD
OSCD is an output timing oscillator input pin.
It’s connected to an external RC to obtain the
desired output turn-on duration. Variable output turn-on durations can be achieved by selecting various values of RC or using a variable
resistor.
TD=
CDS
Status
PIR
LOW
Day Time
Disabled
HIGH
Night
Enabled
1
× 21504
f
Fig.2 Output timing oscillator
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HT761X
MODE
ZC
MODE is a tri-state input pin used to select the
operating mode.
ZC is a CMOS input structure. It receives AC
line frequency and generates zero crossing
pulses to synchronize the triac driver. By effective ZC signal switching (switch OFF/ON 1 or 2
times within 3 seconds by mask option), the
chip provides the following additional functions:
MODE Operating
Status
Mode
VDD
VSS
Open
ON
Description
Output is always ON:
RELAY outputs high for
relay driving.
TRIAC pulse train output
is synchronized by ZC for
triac driving.
OFF
Output is always OFF:
RELAY outputs low for
relay driving.
TRIAC outputs high for
triac driving.
AUTO
Outputs remain in the off
state until activated by a
valid PIR input trigger
signal. When working in
the AUTO mode, the chip
allows override control by
switching the ZC signal.
• Test mode control
Within 10 seconds after power-on, effective
ZC switching will force the chip to enter the
test mode. During the test mode, the outputs
will be active for a duration of 2 seconds each
time a valid PIR trigger signal is received. If
a time interval exceeds 32 seconds without a
valid trigger input, the chip will enter the
AUTO mode automatically.
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24th Mar ’97
HT761X
• Override control
there is no further override operation, it will
return to AUTO automatically after an internal preset ON time duration has elapsed. This
override ON time duration can be set to 4 or 6
or 8 hours by mask option. The default is 8
hours.
When the chip is working in the AUTO mode
(MODE=open), the output is activated by a
valid PIR trigger signal and the output active
duration is controlled by the OSCD oscillating
period. The lamp can be switched always to
“ON” from the AUTO mode by either switching the MODE pin to VDD or switching the ZC
signal by an OFF/ON operation of the power
switch (OFF/ON once or twice within 3 seconds by mask option). The term "override"
refers to the change of operating mode by
switching the power switch. The chip can be
toggled from ON to AUTO by an override operation. If the chip is overridden to ON and
The chip provides a mask option to decide the
output flash times (3 times) when changing
the operating mode. It will flash 3 times at a
1Hz rate each time the chip changes from the
AUTO mode to another mode or flash 3 times
at a 2Hz rate when returning to the AUTO
mode. But if the AUTO mode is changed by
switching the MODE switch it will not flash.
Fig.3 ZC override timing
RSTB
Power on initial
RSTB is used to reset the chip. It is internal
pull-high and active low.
The PIR signal amplifier requires a warm up
period after power-on. The input should be disabled during this period.
The use of CRST can extend the power-on initial
time. If the RSTB pin is an open circuit (without
CRST), the initial time is the default (40 secs).
In the AUTO mode within the first 10 seconds
of power-on initialization, the chip allows override control to enter the test mode. After 40
seconds of the initial time the chip allows override control between ON and AUTO. It will
remain in the warm up period if the total initial
time has not elapsed after returning to AUTO.
In case that the ZC signal disappears more than
3 seconds, the chip will restart the initialization
operation. However, the restart initial time is
always 40 seconds and cannot be extended by
adding CRST to the RSTB pin as shown in Fig.4.
Fig.4 RSTB application example
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HT761X
Mask options
The HT761X offers mask options to select the
output flash (3 times) when changing the operating mode. The chip will flash 3 times at a 1Hz
rate each time it changes from AUTO to another
mode and flash 3 times at a 2Hz rate when it
returns to the AUTO mode. However the chip
will not flash if the mode is changed by switching the MODE switch.
• 4, 6, or 8 hour options to return to AUTO from
override ON. The default is 8 hours.
• Options for effective override: Once or twice
OFF/ON operation of power switch within 3
seconds. The default is OFF/ON twice.
• Options for output flash to indicate effective
override operation. The default is to flash.
• Options for effective PIR trigger pulse width:
>24mS, >32mS or >48mS. The default is 24ms.
• Options for setting comparator window to be
1
1
1
,
or
(VDD–VEE). The default is
16 11.3
9
1
(VDD–VEE).
16
Fig. 5 PIR amplifier
stage amplifying device. The non-inverting input of OP2 is connected to the comparator’s
window centerpoint and can be used to check
this voltage and to provide a bias voltage that is
equal to the centerpoint voltage of the comparator. In Fig.5 the comparator can have 3 window
1
levels set by mask option. 1.
(VDD–VEE), 2.
16
1
1
(VDD–VEE), 3. (VDD–VEE). If the win11.3
9
dow level fails to be specified the default win1
dow is set to
(VDD–VEE). The preset voltage
16
of VDD–VEE is 4V. The default values of VCP
4
and VCN are therefore 0.25V, (
V ).
16
PIR amplifier
Consult the diagram below for details on the
PIR front end amplifier.
In Fig.5 there are 2 op-amps with different
applications. OP1 can be used independently as
a first stage inverting or non-inverting amplifier for the PIR.
As the output of OP2 is directly connected to the
input of the comparator, it is used as a second
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24th Mar ’97
HT761X
Second stage amplifier
Fig.6 Typical second stage amplifier
Usually the second stage PIR amplifier is a
simple capacitively coupled inverting amplifier
with a low pass configuration. The noninverting
input terminal is biased to the center point of
the comparator window and the output of the
second stage amplifier is directly coupled to the
comparator center point.
Fig.7 and Fig.8 are similar but in Fig.8 the
input signal of amplifier is taken from the drain
of the PIR. This has higher gain than that in
Fig.7. Since OP1 is a PMOS input VD has to be
greater than 1.2V for adequate operation.
In Fig.6 OP2P is directly connected to the comparator window center, and with the C3 filter it
can act as the bias for OP2. For this configuraR2
1
tion AV =
, low cutoff frequency fL =
,
R1
2πR1C1
1
high cutoff frequency fH =
. By chang2πR2C2
ing the value of R2 the sensitivity can be varied.
C1 and C3 should be of low leakage types to
prevent the DC operating point from change
due to current leakage.
Fig. 7 Typical first-stage PIR
Each op-amp current consumption is approximately 5µA with the op-amps and comparator’s
working voltage all provided by the regulator.
Consult the following diagrams for typical PIR
front end circuit.
First stage of PIR amplifier
Fig.7 shows a typical first stage amplifier. C2
and R2 form a simple low pass filter with cut off
frequency at 7Hz. The low frequency response
is governed by R1 and C1 with cut-off frequency
at 0.33Hz.
A V=
( R1+ R2 )
R1
Fig.8 High gain first stage
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HT761X
Application Circuit
HT761XA relay application
Note: 1. Adjust R13 to fit various CDS.
2. Change C6 to obtain the desired adjusting range of output duration.
3. Change the value of C11 to 0.33µF/600V for AC 220V application.
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HT761X
HT761XB triac application
Note: 1. Adjust R10 to fit various CDS.
2. Change C7 to obtain the desired adjusting range of output duration.
3. Change the value of C10 to 0.15µF/600V for AC 220V application.
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24th Mar ’97
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