AK7740ET Datasheet, PDF (46/48 Pages) Asahi Kasei Microsystems – 24bit 2ch ADC + 24bit 4ch DAC with Audio DSP

[ASAHI KASEI]
Signal
10k
+10V
10k
-
+
-10V
10k
10k
-
+
+
NJM5532D
4.7u
+
Vop = VA+ = 3.3V
4.7u
[AK7740ET]
2.00Vpp
AIN+
AIN-
2.00Vpp
Signal
Fig. 1 Example of input buffer circuit (differential input)
10k
+10V
10k
-
+
-10V
10k
10k
-
+
+
NJM5532D 4.7u
2.00Vpp
AIN
Vop = VA+ = 3.3V
Fig. 2 Example of input buffer circuit (single ended input)
An analog signal can be applied to the AK7740 in single ended mode. In this case, apply the analog signal (the full
scale is 2.0Vpp when the internal reference voltage is used). However, use of a low saturation operational amplifier is
recommended if the operational amplifier is driven by the 3.3-volt power supply.
9-2-6) Analog output
Analog output is single-ended, and the output range is 2.00Vpp (typical) with respect to VCOM voltage. The
out-of-band noise (from the noise shaper) produced by the internal ∆Σ modulator is reduced by the internal switched
capacitor filter (SCF) and continuous time filter (CTF). It is not necessary to add an external filter for normal
applications. The input code format is given in terms of two's complement with the positive full-scale output for the
7FFFFFH (@24bit) input code, and the negative full-scale output for the 800000H (@24bit) input code. VCOM
voltage is output as an ideal value for 000000H (@24bit) input code.
9-2-7) Connection to digital circuit
To minimize noise resulting from the digital circuit, connect low voltage logic to the digital output. The applicable
logic family includes the 74LV, 74LV-A, 74ALVC and 74AVC series.
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2006/10