AK4632 Datasheet, PDF (31/70 Pages) Asahi Kasei Microsystems – 16-Bit ΔΣ Mono CODEC with ALC & MIC/SPK/Video-AMP

ASAHI KASEI
[AK4632]
FCK
0 1 23 4
BICK(32fs)
9 10 11 12 13 14 15 0 1 2 3 4
9 10 11 12 13 14 15 0 1
SDT O( o)
15 14 13 7 7 6 5 4 3 2 1 0
SD T I( i)
15 14 13
76 54 32 1 0
0 1 23 4
BICK(64fs)
14 15 16 17 18
31 0 1 2 3 4 14 15 16 17 18
31 0 1
SDT O( o)
15 14 13
21 0
SD T I( i)
15 14 13
2 10
Don’t Care
15:MSB, 0:LSB
Data
1/fs
Figure 29. Mode 3 Timing
Don’t Care
„ Digital High Pass Filter
The ADC has a digital high pass filter for DC offset cancellation. The cut-off frequency of the HPF is 1.25Hz
(@fs=8kHz) and scales with sampling rate (fs).
„ MIC Gain Amplifier
The AK4632 has a Gain Amplifier for Microphone input. This gain is 0dB, +20dB, +26dB or +32dB, selected by the
MGAIN1-0 bit. The typical input impedance is 30kΩ.
MGAIN1 bit
0
0
1
1
MGAIN0 bit Input Gain
0
0dB
1
+20dB
0
+26dB
1
+32dB
Table 14. Input Gain
Default
„ MIC Power
The MPI pin supplies power for the Microphone. This output voltage is typically 0.75 x AVDD and the load resistance is
minimum 2kΩ. No capacitor must not be connected directly to MPI pin. (See Figure 30)
MIC Power
MPI pin
≥ 2k Ω
MIC pin
Microphone
MIC-Amp
Figure 30. MIC Block Circuit
MS0396-E-00
- 31 -
2005/06