AK8999AD Datasheet, PDF (37/68 Pages) Asahi Kasei Microsystems – Pressure Sensor Control IC

CONFIDENTIAL
[AK8999A/AW/AD]
VO pin
Cutoff
Fig Time (msec)
99% Settling time (ms) ()
Ext. cap Freq.(Hz) _{Typical Worst case}
(nF) (Typical)
case
Note)
Typical
case
Worst case
Note)
1000
1.090
0.512
0.700
672.4
962.5
220
4.955
0.512
0.700
147.9
211.7
22
49.55
0.512
0.700
14.79
21.17
2.2
495.5
0.512
0.700
1.479
2.117
0.22
4.96k
0.512
0.700
0.148
0.212
0.1
10.9k
0.512
0.700
0.067
0.096
Note) External capacitance ± 10% and worst case for lot variations.
99% Settling time (ms) (+)
Typical
case
Worst case
Note)
672.9
963.2
148.4
212.4
15.30
21.87
1.991
2.817
0.660
0.912
0.579
0.796
2.2) Noise Reduction Effects with Band Limitation
The relationship between an external capacitance of the VO pin and noise reduction effect is shown below.
Sampling
Freq.(Hz)
VO pin
Ext. cap (nF)
Typical
Cutoff
Freq.(Hz)
Noise Reduction Effect (dB)
Typical case
Worst case
Note)
1000
1.090
-23.03
-22.30
220
4.955
-16.96
-16.18
0.83k
22
49.55
-7.70
-6.98
2.2
495.5
-1.25
-1.01
No capacitor
-
0.00
0.00
220
4.955
-24.41
-24.39
22
49.55
-16.70
-16.66
8.33k
2.2
495.5
-7.67
-6.96
0.22
4.96k
-1.25
-1.01
No capacitor
-
0.00
0.00
Note) External capacitance ± 10% and worst case for lot variations.
As seen in Sections "2.1) VOUT pin output voltage stabilization time" and "2.2) Noise Reduction Effect with
Band Limitation", the VO pin external capacitance value should be reduced to decrease the measurement
time. The VO pin external capacitance value should be larger to reduce the noise.
On determining the VO pin external capacitance value, various conditions should be thoroughly reviewed
according to the application requirements.
3) Pressure Threshold Detection Operation at Power-Up
Note that pressure threshold detectors operate at power up.
VOUT pin output voltage is settled down based on the time constant determined by the internal resistance
146kΩ and VO pin external capacitance Cap value (see 2) Finding the VOUT and VO Pins External
Capacitance (Cap)). Note that errors may be detected during the time in which VOUT pin output is not
settled down to the voltage required according to the pressure applied.
MS1600-E-00
- 37 -
2014/05