LS6511_06 Datasheet, PDF (3/4 Pages) LSI Computer Systems – PIR SENSOR INTERFACE

FIGURE 2. TYPICAL RELAY APPLICATION
NOTE 1: The relay coil is normally energized and the LED is off.
When an alarm occurs, the relay coil becomes de-energized and
the LED is turned on.
R3
R1 = See NOTE 2
R2 = 36kΩ
R3 = 1.5MΩ
R4 = 36kΩ
R5 = 1.5MΩ
R6 = 2.2MΩ (Typical)
R7 = 2.2MΩ (Typical)
R8 = 2.2MΩ (Typical)
R9 = 36kΩ
R10 = 2.2kΩ (Typical)
C3
-
C4
+
R4
1
AMP 1
OUT
2 _{AMP 2}
(-) IN
C5
R5
AMP 1 ¹⁴
(-) IN
AMP 1 ¹³
(+) IN
R9
+
C2
-
R2
C9
PIR
SENSOR
C1 = 100µF
C2 = 10µF
C3 = 0.003µF
C4 = 10µF
C5 = 0.003µF
D1 = 1N4001
C6 = 0.01µF (Typical)
C7 = 0.22µF (CP Mode; Typical)
C7 = 0.68µF (DPMode; Typical)
C8 = 0.22µF (Typical)
C9 = 0.1µF C10 = 0.1µF
Relay = No typical P/N
PIRs = Perkin-Elmer LHi 958, 978 (Typical)
Nicera RE200B, SDA02-54 (Typical)
V DD
3 _{AMP 2}
OUT
12
5V REG
All Resistors 1/4W. All Capacitors 10V.
RAW
OUT
DC
NOTE 2: R1 is selected to provide sufficient
V DD
R7
d _C7
V DD
e _R8
u _C8
R6
4 _{DIG FILTER}
RC
11
C6
V DD
5
CP MODE or
10
DP MODE RC _{V SS}
See Note 3
LS6511
9
6
DUR TIM
RC
LED/REL
OUT
+
- ^C10
INPUT
R1
+
- ^C1
RELAY
COIL
D1
ntin ^VDD
S
7
LED/REL ^{8 R10}
MODE
OUT
S = 3-Position SPDT (On-Off-On)
LED
current to drive the LS6511 and PIR Sensor.
Any surplus current is available to drive additional
loads applied to the 5V Shunt Regulator output or
is absorbed by the 5V Shunt Regulator. Refer to
specifications for current limits.
NOTE 3: In SP Mode, R7 and C7 are not used and
Pin 5 is tied to Vss.
NOTE 4: Adjust the value of R9 if the selected PIR
Sensor causes the input static voltage at Pin 13 to
be out of the Input Dynamic Range of 0V to 1.75V.
(See Electrical Characteristics on Page 2)
NOTE 5: Sensitivity can be adjusted to a lower
value by increasing the value of R2 or R4 or by
decreasing the value of R3 or R5.
NOISE CONSIDERATIONS
o Layout of any circuit using a high-gain PIR amplifier is critical.
The PIR amplifier components should be located close to the
c ^{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 0.1uF high frequency capacitor across C1
and increasing C1 to 220 µF.
Dis ^{FIGURE 3. INHIBITING OUTPUTS UPON POWER TURN-ON}
V DD
100k
+
220µF
R6
2.2M
C6
.01µF
LS6511 - 4
Using the typical application circuit as shown in Figure 2,
the Outputs on Pins 8 and 9 occur on power-up 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 power-up long enough to enable the PIR
amplifiers to stabilize. Replacing the R6-C6 circuit shown in
Figure 2 with the circuit shown in Figure 3 will disable the
digital filter oscillator until the voltage across the 220µF
capacitor reaches a value high enough for the oscillator to
begin oscillating. Component values that can be changed to
speed up stabilization include C2, C3, C4 and C5. C3 and
C5 become 0.001µF and C2 and C4 become 10µF.
6511-090606-3