CS5507-AS Cirrus Logic Inc, CS5507-AS Datasheet - Page 19

• Manufacturer Part Number: CS5507-AS
• Description: ADC Single Delta-Sigma 100SPS 16-Bit Serial 20-Pin SOIC
• Manufacturer: Cirrus Logic Inc

Specifications of CS5507-AS

• Package: 20SOIC
• Resolution: 16 Bit
• Sampling Rate: 100 SPS
• Architecture: Delta-Sigma
• Number Of Analog Inputs: 1
• Digital Interface Type: Serial
• Input Type: Voltage
• Polarity Of Input Voltage: Unipolar|Bipolar

Digital Filter Characteristics
The digital filter in the CS5505/6/7/8 is the com-
bination of a comb filter and a low pass filter.
The comb filter has zeros in its transfer function
which are optimally placed to reject line interfer-
ence frequencies (50 and 60 Hz and their
multiples) when the CS5505/6/7/8 is clocked at
32.768 kHz. Figures 9, 10 and 11 illustrate the
magnitude and phase characteristics of the filter.
DS59F4
DS59F5
X1
X2
-100
-120
-140
-100
-120
-140
-160
-20
-40
-60
-80
-20
-40
-60
-80
0
0
Figure 9. Filter Magnitude Plot to 260 Hz
Figure 10. Filter Magnitude Plot to 50 Hz
0
0
0
5
198.97
Frequency
40
10
17
10
Flatness
1
2
3
4
5
6
7
8
9
397.95
15
-0.010
-0.041
-0.093
-0.166
-0.259
-0.374
-0.510
-0.667
-0.846
-1.047
-3.093
80
dB
Frequency (Hz)
Frequency (Hz)
20
596.92
XIN = 32.768 kHz
120
25
XIN = 32.768 kHz
795.10
X1 = 32.768kHz
X2 = 163.00kHz
30
160
35
993.87
200
40
1193.85
45
240
50
Figure 9 illustrates the filter attenuation from dc
to 260 Hz. At exactly 50, 60, 100, and 120 Hz
the filter provides over 120 dB of rejection. Ta-
ble 3 indicates the filter attenuation for each of
the potential line interference frequencies when
the converter is operating with a 32.768 kHz
clock. The converter yields excellent attenuation
of these interference frequencies even if the fun-
damental line frequency should vary ±1% from
its specified frequency. The -3 dB corner fre-
quency of the filter when operating from a
32.768 kHz clock is 17 Hz. Figure 11 illustrates
that the phase characteristics of the filter are pre-
cisely linear phase.
Table 3. Filter Notch Attenuation (XIN = 32.768 kHz)
Frequency
-135
-180
180
135
-45
-90
90
45
(Hz)
100
120
150
180
200
240
0
50
60
0
Figure 11. Filter Phase Plot to 50 Hz
5
10
Notch
Depth
125.6
126.7
145.7
136.0
118.4
132.9
102.5
108.4
(dB)
15
Frequency (Hz)
20
Frequency
25
100±1%
120±1%
150±1%
180±1%
200±1%
240±1%
50±1%
60±1%
(Hz)
CS5505/6/7/8
30
XIN = 32.768 kHz
CS5505/6/7/8
35
Attenuation
Minimum
40
104.4
(dB)
55.5
58.4
62.2
68.4
74.9
87.9
94.0
45
19
19
50