ZSBI010SZ000SC Zilog, ZSBI010SZ000SC Datasheet - Page 18

• Manufacturer Part Number: ZSBI010SZ000SC
• Description: IC ASSP PIR AMPLIFIER 8-SOIC
• Manufacturer: Zilog
• Type: Sensor Interfacer

Specifications of ZSBI010SZ000SC

• Applications: Passive Infrared (PIR)
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 269-3120

5.3 C
5.3.1 Using the Window Comparator for the Control Circuitry
18
ONTROL
S
YSTEM
B
LOCK
D
For an F
An RC low-pass Þlter at the PIR ampliÞer output Þlters the 10- to 15-Hz signal.
The cutoff frequency (F
With a cutoff frequency approximately equal to 16 Hz, the values of R1 and C2
are recommended to be 100 k and 0.1 µF, respectively.
The output of the PIR ampliÞer is connected to the Control Block for motion
detection control. Because the output from the PIR ampliÞer is an analog signal,
analog-to-digital signal conversion is required. The analog-to-digital conversion
is achieved either by using simple comparators (converted to 0 or 1 only) or an
ADC. The output from the ADC connects to the control circuitry, which can be
one or more switches, or a microcontroller.
Figure 6 illustrates the control circuitry using window comparators. Resistors R
R
motion detection. The comparator output is used for switches or other control cir-
cuitry. Upper and Lower Threshold are calculated as follows:
F
Upper Threshold Voltage =
Lower Threshold Voltage =
IGURE
ESIGN
M
, and R
F
C
~ 1 ÷ (2 R1C2)
6. C
C
LOW
ONSIDERATIONS
L
OMPARATOR
are used to setup the Upper Threshold and Lower Threshold for
value close to DC, the value of R3 is recommended to be 50 k
ZSBI010 PRELIMINARY
Input
C
C
) of the RC Þlter is calculated as follows:
ONTROL
R
R
R
H
M
L
R
R
V
H
H
DD
C
R
+ R
+ R
IRCUITRY
M
R
+ R
M
M
L
the Window Comparator
+ R
+ R
+
–
+
–
L
Control Block Using
L
L
Control Signals
x V
x V
DD
DD
PS002301-SEC1099
C
ONTROL
B
LOCK
H
,