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COMMERCIAL CARBON DIOXIDE SENSOR, 400 PPM TO
2000 PPM (UP TO 5000 PPM EXTENDED RANGE),
TABLE 4. TERMINATION (VDD = 3.3 V NOMINAL) (Continued)
PIN
PIN
NUMBER
FUNCTION
bCAL_in
5
/CAL
6
PWM
7
Alarm_OC
The specified parameter relies on the subcontractor's specification and is not tested by Honeywell.
1
DESCRIPTION
digital input forcing background or zero calibration
background calibration: when closed for
minimum 4 s, maximum 8 s, bCAL
(background calibration) assuming 400 ppm
CO
exposure.
2
zero calibration: when closed for minimum 16 s
CAL (zero calibration) assuming 0 ppm CO
exposure.
absolute maximum voltage range
internal pull down to GND resistor
input low level
1
input high level
1
PWM output configured as digital output used for
direct reading by customer's microcontroller or to
provide analog output.
normal concentration range
PWM cycle time
beginning of each cycle
end of each cycle
relationship between CO
2
and PWM output
PWM resolution
absolute maximum voltage range
internal pull down to GND resistor
output low level
1
output high level
1
open collector output for alarm indication
absolute maximum voltage range
internal pull up to G+ resistor
maximum sink current
1
saturation voltage
1
2
1
concentration (ppm)
1
1
CRIR E1
ELECTRONIC SPECIFICATION
no internal protection, pulled up to VDD
processor reset (power up and power down)
GND to VDD + 0.5 V
120 k
GND to 0.75 V
2.3 V to VDD + 0.3 V
no internal protection, pulled down at processor
reset (power up and power down)
400 ppm to 2000 ppm
1004 ms ± 5%
high level output, 2 ms
low level output, 2 ms
C(CO
) = 2000 x (T
-2) / (T
H
2
T
: time (ms) of high level output in a cycle
H
T
: time (ms) of low level output in a cycle
L
0.5 ms ± 4%
GND to VDD + 0.5 V
120 k
0.4 VDC maximum at 8 mA sink
2.4 VDC minimum at 8 mA source
no internal protection, pulled up to G+ at processor
reset (power up and power down)
GND to 5 V + 0.5 V
10 k
100 mA
2.3 V to Vin + 0.3 V
Sensing and Internet of Things
Issue 1
000841
at
2
+T
-4)
H
L
5
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