AK5393 Datasheet, PDF (16/18 Pages) Asahi Kasei Microsystems – Enhanced Dual bit 96 kHz 24-bit ADC

ASAHI KASEI
[AK5393]
Figure 7shows an input buffer circuit example 1. This is a full-differential input buffer circuit with an inverted-amp
(gain :-10dB). The capacitor of 10nF between AIN+ /- decreases the clock feed through noise of modulator, and composes
a 1st order LPF(fc=360kHz) with 22ohm resistor before the capacitor. This circuit also has a 1st order LPF(fc=370kHz)
composed of op-amp. In this example, the internal offset is removed by self calibration. The evaluation board should be
referred about the detail.
4.7k
910
Analog In
8.1Vpp
4.7k ^VP+
-
47µ
3k
+
VP-
Bias
470p
-
+
AK5393
22 _2.45Vpp
AIN+
NJM5532
910
10n
VA+
10k
47µ
VA=±5V
VP=±15V
Bias
470p
3k
-
+
Bias
22
AIN-
2.45Vpp
CAL
+
10k
10µ
0.1µ
"L" at self calibration
ZCAL
Figure 7 Differential Input Buffer Example 1
Figure 8 shows an input buffer circuit example 2. (1^st order HPF; fc=0.66Hz, Table 4, 1^st order LPF; fc=590kHz, gain=-
14dB, Table 5). The analog signal is able to input through XLR or BNC connectors. (short JP1 and JP2 for BNC input, open
JP1 and JP2 for XLR input). The input level of this circuit is +/-12.4Vpp (AK5393: +/-2.45Vpp Typ.).
BNC
4.7k
JP1
4.7k
12.4Vpp
Vin+
22u 1k
VA
XLR
4.7k
0.1u
4.7k
10u
180
-
+
NJM5534
10k
Bias
1.5n
10k
JP2
-
+
Vin-
NJM5534 12.4Vpp
22u 1k
180
-
+
NJM5534
Figure 8 Differential Input Buffer Example 2
AK5393 AIN+
2.45Vpp
100
2.45Vpp
AK5393 AIN-
M0038-E-04
fin
1Hz
10Hz
Frequency Response -1.56dB -0.02dB
Table 4. Frequency Response of HPF
fin
20kHz
40kHz
Frequency Response -0.005dB -0.02dB
Table 5. Frequency Response of LPF
6.144MHz
-15.6dB
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