AK5394AVS AKM [Asahi Kasei Microsystems], AK5394AVS Datasheet - Page 22

• Manufacturer Part Number: AK5394AVS
• Description: Super High Performance 192kHz 24-Bit ADC
• Manufacturer: AKM [Asahi Kasei Microsystems]

ASAHI KASEI
6. Noise floor of AK5394A
The AK5394A has a sprious noise of about 135dBFS on the noise floor of Lch output at no signal input. When this noise
causes a trouble in system, it can be removed by adding a minute offset to the analog inputs of both channels externally
using a circuit as Figure 13. The relationship between the frequency range (f
adding offset voltage (V
A resistor, R in Figure 13 should be 8 to add an offset of 2mV to the analog inputs. The relationship between R and V
is shown by the following equation.
An offset voltage of the op-amps should be considered in the actual circuit. For example, when removing the sprious noise
of 20kHz or less, the adding offset voltage should be 2+2=4mV if the op-amp has an offset of +/ 2mV. In this case, the
dynamic range of the ADC output decreases 4mV.
MS0137-E-01
10k
10k
R
5V
10
+
µ
0.1
of
Bias+
Bias-
) is f
µ
T
[kHz] = 20 x V
Table 10. Sprious noise Frequency vs. Offset voltage
Sprious noise Frequency
Vin-
Figure 13. Removing the sprious noise circuit
0
0
0
Vin+
20kHz
40kHz
80kHz
of
V
68µ
68µ
XLR
[mV]
of
Bias+
20
3.3k
3.3k
20. The example is shown in Table 10.
- 22 -
Bias-
k
R
NJM5534
NJM5534
R
+
-
-
+
620
620
1n
[ 5
1n
Offset Voltage
V
]
+2mV
+3mV
+5mV
91
91
T
) of the sprious noise to be removed and the
2.2n
AK5394A AIN-
AK5394A AIN+
[AK5394A]
2002/07
of