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 24th Mar ’97 HT761X Pin Assignment Block Diagram 2 24th Mar ’97 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. 3 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 4 24th Mar ’97 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. 5 24th Mar ’97 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 6 24th Mar ’97 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. 7 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 8 24th Mar ’97 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 9 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 10 24th Mar ’97 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. 11 24th Mar ’97 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. 12 24th Mar ’97