Datasheet

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V
IN
L
1
3
4
V
REF
1
V
REF
2
0.1 µF
+
1 µF
20 kΩ
+
−
+
−
Delta-Sigma
Modulator
(+)
(−)
Reference
5
V
CC
+
10 µF
S0011-05
1
st
SW-CAP
Integrator
Analog
In
X(z)
+
−
+
−
2
nd
SW-CAP
Integrator
3
rd
SW-CAP
Integrator
+
−
4
th
SW-CAP
Integrator
+
+
+
+
+
+
+
+
5
th
SW-CAP
Integrator
Digital
Out
Y(z)
Comparator
Qn(z)
H(z)
1-Bit
DAC
STF(z) = H(z) / [1 + H(z)]
NTF(z) = 1 / [1 + H(z)]
Y(z) = STF(z) * X(z) + NTF(z) * Qn(z)
Signal Transfer Function
Noise Transfer Function
B0005-02
PCM1802
SLES023C – DECEMBER 2001 – REVISED JANUARY 2005
PRINCIPLES OF OPERATION (continued)
Figure 20. Analog Front End (Left Channel)
Figure 21. Block Diagram of Fifth-Order Delta-Sigma Modulator
12