AK5700 Datasheet, PDF (32/61 Pages) Asahi Kasei Microsystems – 16-Bit ΔΣ Mono ADC with PLL & MIC-AMP

ASAHI KASEI
[AK5700]
„ Digital High Pass Filter
The ADC has a digital high pass filter for DC offset cancellation. The cut-off frequency of the HPF is selected by HPF1-0
bits (see Table 17) and scales with sampling rate (fs). The default value is 3.4Hz (@fs=44.1kHz).
HPF1 bit
0
0
1
1
HPF0 bit
0
1
0
1
fc
fs=44.1kHz
fs=22.05kHz
3.4Hz
1.7Hz
6.8Hz
3.4Hz
13.6Hz
6.8Hz
N/A
N/A
Table 17. Digital HPF Cut-off Frequency
fs=11.025kHz
0.85Hz
1.7Hz
3.4Hz
N/A
Default
„ MIC/LINE Input Selector
The AK5700 has input selector. When MDIF1 bit is “0”, AIN bit selects AIN1or AIN2. When MDIF1 bit is “1”, AIN1pin
become AIN+ pin . In this case, full-differential input is available (Figure 33). When full-differential input is used, the
signal should not be input to the pins marked by “X” in Table 19.
MDIF1 bit
AIN bit
Ach
0
AIN1
AIN1
0
1
AIN2
AIN2
0
AIN1
1
N/A
1
x
N/A
AIN+/−
x
AIN+/−
Table 18. MIC/Line In Path Select
Default
Register Pin
MDIF1 bit
AIN1
AIN1+
AIN2
AIN1−
0
O
O
-
1
O
X
O
Table 19. Handling of MIC/Line Input Pins (“-“: N/A; “X”: Signal should not be input.)
AK5700
AIN1/AIN+ pin
AIN− pin
AIN2 pin
AIN bit
MDIF1 bit
ADC
Figure 32. Mic/Line Input Selector
MS0569-E-01
- 32 -
2006/12