LSI Computer Systems, Inc Walt Whitman Road, Melville, NY (631) FAX (631) PIR SENSOR INTERFACE

Transcription

1 LSI/CSI LS6N LS6 LS6 UL LSI Computer Systems, Inc. Walt Whitman Road, Melville, NY 77 (6) 7000 FAX (6) 700 A800 SENSOR INTERFACE September 009 FEATURES: Direct Interface with Sensor TwoStage Differential Amplifier Amplifier Gain and Bandwidth externally controlled True and Complementary Output Drives Separate digital filters for processing positive and negative input signals Single Pulse/Dual Pulse/ Concurrent Pulse Detection Adjustable Output Pulse Width Optional V Shunt Regulator Output 7µA Typical Supply Current Undervoltage Detection LS6N(DIP); LS6NS (SOIC) See Figure A LS6(DIP); LS6S (SOIC) See Figure A LS6(DIP); LS6S (SOIC) See Figure B APPLICATIONS: Security system intrusion detection, automatic doors, motion triggered events such as remote animal photography, etc. DESCRIPTION (See Figure ) The LS6N, LS6 and LS6 are CMOS integrated circuits designed for detecting motion from a Sensor and initiating appropriate responses. DIFFERENTIAL AMPLIFIER Each stage of the two stage Differential Amplifier can be set to have its own amplification and bandwidth. The two inputs to the first stage allow for singleended or differential connection to Sensors. This stage can be biased anywhere in its dynamic range. The second stage is internally biased so that the Window Comparator s lower and higher thresholds can be fixed relative to this bias. Signal levels as low as 00µV can be detected. WINDOW COMPARATOR The Window Comparator provides noise filtering by enabling only those signals equal to or greater than a fixed threshold at the output of the Differential Amplifier to appear at the outputs of the Window Comparator. One output detects positive input signals while the other output detects negative input signals. COMPARATOR DIGITAL FILTER The outputs of the Window Comparator are filtered so that motion must be present for a certain duration before it can be recognized and appear as pulses at the Digital Filter outputs. An external RC network sets the duration time. Nominal duration is 0ms. A tristate input pin selects how the detected signals are processed. Single Pulse (SP) Mode is when detection from either a positive or negative input signal at the Digital Filter outputs will cause an LED / RELAY output to occur. Concurrent Pulse (CP) Mode is when detection from a positive and negative input signal must occur within a specific time before an output will occur. Dual Pulse (DP) mode is when any two detections within a specific time will cause an output to occur. SP Mode = 0; CP Mode = Open; DP Mode =. 6N0909 PROGRAMMABLE RETRIGGERABLE ONESHOTS Positive and negative input signals at the digital filter outputs will generate retriggerable oneshot pulses. In the Concurrent Pulse Mode, outputs from each oneshot must occur together at some point in time to cause an output to occur. The oneshot pulse width is programmable using an external RC network. Typical pulse widths used vary between and seconds. WINDOW TIMER In the Dual Pulse Mode any two detections must occur within a timing window to cause an output to occur. The timing window is programmable using an external RC network. Typical windows are between and seconds. ENABLE Input A low on the Enable input for LS6 allows the LED / Relay and LED / Relay outputs to respond to the input detection. If the Enable input is high, then the two outputs remain in their dormant state. The LED / Relay and LED / Relay outputs on LS6N and LS6 are always enabled. SEL UDV Input For the LS6, a low on this input allows undervoltage to be detected. If left floating, undervoltage detection will not occur. PUT DURATION TIMER The duration timer is retriggerable and programmable using an external RC network. Typical duration times are between 0. and seconds. Successive input detections will restart the timer. PUTS The LED / RELAY Output is an open drain output that will sink current when an input signal is detected and processed. The LS6N will also sink current when the Power Supply drops below.v (Typical) (Undervoltage Detection). The Undervoltage Detection will be removed when the Power Supply rises above.7v (Typical). The LED / RELAY Output performs identically but is opposite in polarity. The output can sink current from a relay coil returned to a positive voltage (VDD to V maximum). The LS6 will not respond to an undervoltage detection. The LS6 can be selected to respond or not respond to a power supply undervoltage. The undervoltage detection feature in the LS6N assures that in security systems tampering with the power supply by loading it and causing it to be reduced in value will be quickly detected. In battery operated nonsecurity systems applications the undervoltage feature is not desireable because it produces unwanted outputs as the batteries age. The LS6 should be selected for these applications. SHUNT REGULATOR The LS6N includes a V Shunt Regulator Output which can be tied to the Pin so that the circuit can be powered from a higher voltage power supply. Note: See Figures, and for application schematics.

2 PIN ASSIGNMENT TOP VIEW DIFF. AMP. PUT LSI DIFF. INPUT () DIFF. AMP. INPUT () DIFF. INPUT () DIFF. AMP. PUT CP MODE / DP MODE RC LS6N LS6 0 V REGULATOR PUT VDD (V) V SS ( V) DURATION TIMER RC 6 9 LED / RELAY PUT 7 8 LED / RELAY PUT FIGURE A PIN ASSIGNMENT TOP VIEW DIFF. AMP. PUT DIFF. AMP. INPUT () LSI 6 DIFF. INPUT () DIFF. INPUT () DIFF. AMP. PUT V REGULATOR PUT CP MODE / DP MODE RC LS6 VDD (V) V SS ( V) DURATION TIMER RC 6 LED / RELAY PUT 7 0 LED / RELAY PUT ENABLE 8 9 SEL UDV INPUT FIGURE B The information included herein is believed to be accurate and reliable. However, LSI Computer Systems, Inc. assumes no responsibilities for inaccuracies, nor for any infringements of patent rights of others which may result from its use. 6N07009

3 ABSOLUTE MAXIMUM RATINGS: PARAMETER SYMBOL VALUE UNIT DC supply voltage VDD VSS 7 V Any input voltage VIN VSS 0. to VDD 0. V Operating temperature TA 0 to 8 C Storage temperature TSTG 6 to 0 C ELECTRICAL CHARACTERISTICS: (All voltages referenced to VSS, TA = 0 C to C,.V VDD 6.V, unless otherwise specified.) PARAMETER SYMBOL MIN TYP MAX UNIT CONDITIONS SUPPLY CURRENT: VDD = V IDD 7 00 µa LED/RELAY, LED/RELAY VDD =.V 6.V IDD 60 µa and REGULATOR outputs not loaded REGULATOR: Voltage VR V Current IR ma UNDERVOLTAGE: DETECTION UDV.9.. V } LS6N RECOVERY URV.0.7. V } LS6 MIN. OPERATING VOLTAGE VDM.0 V } LS6 } LS6 DIFFERENTIAL AMPLIFIERS: Open Loop Gain, Each Stage G 70 db Common Mode Rejection Ratio CMRR 60 db Power Supply Rejection Ratio PSRR 60 db Input Sensitivity VS 00 µvpp TA = C, with Amplifier (Minimum Detectable Voltage Bandpass configuration to first amplifier when both as shown in Figure amplifiers are cascaded for a net gain of 8,000) Input Dynamic Range 0.7 V Diff. Amp Internal VIR 0.VDD V Reference COMPARATOR: Lower Reference VTHL VIR 0.V V At VDD =.0V Higher Reference VTHH VIR 0.V V At VDD =.0V DIGITAL FILTER: For 0ms Filter Time RDF. MΩ CDF 0.0 µf ONE SHOT ROS. MΩ ( Second) COS 0. µf WINDOW TIMER RWT. MΩ (. Second) CWT 0.68 µf Concurrent Pulse TCP sec RCP <.MΩ } Window CCP = 0.uF } } Pin Dual Pulse TDP. sec RDP =.MΩ } Window CDP = 0.68uF } DURATION TIMER TDT sec RDT =.MΩ } Pin 6 CDT = 0.68µF } PUT DRIVE CURRENT IO 0 ma VDD = V (VO = 0.V Max.) IO 0 ma VDD = VDM 6N0909

4 FIGURE. TYPICAL RELAY APPLICATION NOTE : The relay coil is normally energized and the LED is off. When an alarm occurs, the relay coil becomes deenergized and the LED is turned on. R8 C8 R7 C7 C R C R R6 C6 S = Position SPDT (OnOffOn ) See Note S 6 7 (8) () IN R C DIG FILTER RC CP MODE or DP MODE RC LS6N/LS6 (LS6 ) DUR TIM RC MODE ENABLE () IN () IN V REG V SS LED / REL LED / REL SEL UDV IN (6) () () () 0 () 9 () 8 (0) ( 9) R0 R9 C0 LED C R C9 C RELAY COIL D R SENSOR RAW DC INPUT R = See NOTE R = 6kΩ R =.MΩ R = 6kΩ R =.MΩ C = 00µF C = 0µF C = 0.00µF C = 0µF C = 0.00µF D = N00 R6 =.MΩ (Typical) R7 =.MΩ (Typical) R8 =.MΩ (Typical) R9 = 6kΩ R0 =.kω (Typical) C6 = 0.0µF (Typical) C7 = 0.µF (CP Mode; Typical) C7 = 0.68µF (DPMode; Typical) C8 = 0.µF (Typical) C9 = 0.µF C0 = 0.µF Relay = No typical P/N = PerkinElmer LHi 98, 978 (Typical) Nicera RE00B, SDA0 (Typical) All Resistors /W. All Capacitors 0V. NOTE : R is selected to provide sufficient current to drive the LS6N and Sensor. Any surplus current is available to drive additional loads applied to the V Shunt Regulator output or is absorbed by the V Shunt Regulator. Refer to specifications for current limits. NOTE : In SP Mode, R7 and C7 are not used and Pin is tied to Vss. NOTE : Adjust the value of R9 if the selected Sensor causes the input static voltage at Pin to be out of the Input Dynamic Range of 0V to.7v. (See Electrical Characteristics on Page ) NOTE : Sensitivity can be adjusted to a lower value by increasing the value of R or R or by decreasing the value of R or R. NOTE 6: Pins shown in parentheses and connections shown by broken lines are for LS6 only. NOISE CONSIDERATIONS Layout of any circuit using a highgain amplifier is critical. The amplifier components should be located close to the amplifier pins on the chip in order to minimize noise pickup.the oscillator and relay drive components should be located away from the amplifier components. Other steps that can help reduce noise is adding a ground shield backplane to the PCB and enhancing the filtering of VDD; i.e., adding a 0.uF high frequency capacitor across C and increasing C to 0 µf. FIGURE. INHIBITING PUTS UPON POWER TURNON 0k 0µF R6.M C6 0.0µF LS6N Using the typical application circuit as shown in Figure, the Outputs on Pins 8 and 9 occur on powerup because of the large settling time in the amplifier stages. In applications where this is not desireable, the digital filter oscillator must be disabled on powerup long enough to enable the amplifiers to stabilize. Replacing the R6C6 circuit shown in Figure with the circuit shown in Figure will disable the digital filter oscillator until the voltage across the 0µF capacitor reaches a value high enough for the oscillator to begin oscillating. Component values that can be changed to speed up stabilization include C, C, C and C. C and C become 0.00µF and C and C become 0µF. 6N0609

5 FIGURE. DIFFERENTIAL INTERFACE TO SENSOR PAIR R C C C R R () IN () IN () IN (6) R C R7 C8 () R6 C6 R0 C9 R8 R9 C7 SENSOR SENSOR V REG LS6N / LS6 (LS6 ) (6) C0 C R V R = kω R6 = 6kΩ C = 00µF C6 = 0µF R =.MΩ R7 = 6kΩ C = 0.00µF C7 = 0.0µF R = 6kΩ R8 = 6kΩ C = 0µF C8 = 0.µF R =.MΩ R9 =.6MΩ C = 0.00µF C9 = 0.µF R = 6kΩ R0 =.MΩ C = 0µF C0 = 0.µF s = PerkinElmer LHi 9, 98, 978; Nicera RE00B, SDA0 (Typical) All Resistors / W. All Capacitors 0V. NOTES: ) A pair of Sensors may be used in applications where a wider optical field of view is needed. ) External V Regulator drives the LS6N and sensor. FIGURE. BLOCK DIAGRAM DIFF PUT ENABLE DURATION TIMER RC MODE SELECT DIFF INPUT () DIFF PUT DIFF INPUT () DIFF INPUT () AMP VDD AMP WINDOW COMPARATOR COMP COMP DIGITAL FILTER DIGITAL FILTER PUT DURATION TIMER WINDOW TIMER M U X DRIVER LED/RELAY PUT VDD VSS (V) ( V) SHUNT REGULATOR PROGRAMMABLE RETRIGGERABLE ONESHOT DRIVER LED/RELAY PUT V REGULATOR PUT CONCURRENT PULSE/ DUAL PULSE RC PROGRAMMABLE RETRIGGERABLE ONESHOT UNDERVOLTAGE DETECTOR SEL UDV 6N060909