Cirrus Logic AN263 - Manual (Page 3)

AN263
AN263REV1 3
Figure 2. Effective Conversion System Gain
2.3 Equivalent System Noise Calculation
The output referred system noise voltage (V
nsys
) can be calculated using the expressions for the gain co-
efficient, equivalent ADC and DAC noise voltages.
Where:
Following substitution and simplification:
DAC ADC K
V
fsadc
V
fsdac
K
V
fsdac
V
fsadc
---------------- =
V
nsys
V
ndac
2
K V
nadc
× ( ) 2
+
( )
=
V
ndac
V
fsdac
10
DR
dac
20
---------------- ⎝ ⎠
⎛ ⎞
------------------------ =
V
nadc
V
fsadc
10
DR
adc
20
---------------- ⎝ ⎠
⎛ ⎞
------------------------ =
K
V
fsdac
V
fsadc
---------------- =
V
nsys
V
fsdac
10
DR
dac
10
---------------- ⎝ ⎠
⎛ ⎞
–
10
DR
adc
10
---------------- ⎝ ⎠
⎛ ⎞
–
+ =