ADUC7032_15 Datasheet, PDF (63/128 Pages) Analog Devices – MicroConverter Integrated, Precision Battery Sensor

Preliminary Technical Data
H(f) ⁰
[dB]
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
0
f
20
40
60
80
100
120
140
160
180
200
Figure 23 Typical Digital Filter Response at FADC=8KHz, (ADCFLT = 0x961F)
Changing SF to 0x1D and setting AF to 0x3F, again with the
Chop bit enabled, configures the ADC into its minimum
through-put rate in Normal Mode of 4Hz. The digital filter
frequency response with this configuration is shown below in
Figure 24.
H(f) ⁰
[dB]
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
f
0
20
40
60
Figure 24 : Typical Digital Filter Response at FADC=4Hz, (ADCFLT = 0xBF1D)
In ADC Low Power Mode, the ADC, Sigma-Delta modulator
clock no longer driven at 512KHz but is driven directly from
the on-chip low power (131KHz) oscillator. Subsequently, for
the same ADCFLT configurations in Normal Mode, all filter
values should be scaled by a factor of approximately 4. This
means that is possible to configure the ADC for 1Hz through-
put is Low Power Mode. The filter frequency response for this
configuration is shown below in Figure 25.
ADuC7032
H(f) ⁰
[dB]
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
f
0
2
4
6
8
10
12
14
16
18
20
Figure 25 : Typical Digital Filter Response at FADC=1Hz, (ADCFLT = 0xBD1F
In general, it should be noted that it is possible to program
different values of SF and AF in the ADCFLT register and
achieve the same ADC update rate. In practical terms the trade-
off with any value of ADCFLT will be frequency response
versus ADC noise. For optimum filter response and ADC noise
when using combinations of SF and AF, a good rule of thumb
to use would be to first choose an SF in the range of 16 – 40
(dec) or 0x10 to 0x28 and then increase the AF value to
achieve the required ADC through-put. Table 32 shows some
common ADCFLT configurations.
ADC
Mode
Table 32 : Common ADCFLT Configurations
SF
AF
Other
Config
ADCFLT
FADC
TSETTLE
Normal 0x1D 0x3F Chop On 0xBF1D
4Hz 0.5secs
Normal 0x1F 0x16 Chop On 0x961F 10Hz 0.2secs
Normal 0x07
Normal 0x07
Normal 0x03
Normal 0x00
Low
Power
Low
Power
Low
Power
0x10
0x10
0x1F
0x00 None
0x0007
0x00
0x00
0x01
Sinc 3
Modifiy
Running
Average
Running
Average
0x0087
0x4003
0x4000
0x03 Chop On 0x8310
0x09 Chop On 0x8910
0x3D Chop On 0xBD1F
1KHz 3msecs
1KHz 3msec
2KHz 2msec
8KHz 0.5ms
20Hz 100ms
10Hz 200ms
1Hz
2sec
Rev. PrD | Page 63 of 128