AK7758VN Datasheet, PDF (16/32 Pages) Asahi Kasei Microsystems – DSP with Stereo CODEC + Mic/Lineout Amp

[AK7758]
8.1.4. ATT Amp + MIC Amp + ADC
(Ta= 25°C; AVDD=LVDD=TVDD1/2=3.3V; AVSS=DVSS=0V; LDOE pin =“H”
Signal Frequency 1kHz; Sampling Rate fs=48kHz; Measurement Frequency =20Hz~20kHz)
Parameter
Min. Typ. Max. Unit
Feedback Resistance (Rf)
10
30
kΩ
ATT Amp Load Capacitance (CL)
20
pF
Phase compensation capacitance (Cc) (Note 18)
10
pF
Resolution
24
bit
Dynamic Characteristics
ATT Amp _{S/(N+D) (-1dBFS) (Note 19) fs=48kHz}
74
84
dB
+
MIC Amp
+
Dynamic Range (-60dBFS)
S/N
fs=48kHz (A-weighted)
fs=48kHz (A-weighted)
88
88
98
98
dB
dB
ADC ^{Inter-Channel Isolation (Note 20)}
90
99
dB
DC Accuracy
Channel Gain Mismatch
0.0
0.3
dB
Note 18. This is the value of external capacitors between the IN1pin and the IN2 pin, and the IN3 pin
and the IN4 pin. They are necessary when using the ATT amplifier.
Note 19. In the case of inputting 5.76 Vpp signal when the external input resistance (Ri) is 47 kΩ, the
Feedback resistance (Rf) is 16 kΩ, external capacitance (Cc) is 47pF and the MIC amplifier
gain is set to 0dB (GMNL/R[3:0] bits = 0x0). (5.76 Vpp x 16kΩ / 47kΩ = 1.96Vpp @ -1dBFS)
Note 20. Indicates inter-channel isolation between Lch and Rch when –1dBFS signal is input.
Note 21. Microphone amplifier gain should be set to 0dB when using the path of ATT-Amp + MIC-Amp
+ ADC. ADC operation is not guaranteed if the microphone amplifier gain is 4dB or more.
Rf
IN1 pin
Rin
Cc
AK7758
CL
IN2 pin
ADC
Lch
ATT-Amp
Lch
ATT-Amp
MIC-Amp
Lch
Rin
Lch
IN3 pin
Cc
Rf _CL
IN4 pin
MIC-Amp
Lch
Figure 5. Connection Diagram when using ATT-AMP
ADC
Rch
016003563-E-02-PB
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2016/09