AK7755EN_16 Datasheet, PDF (106/109 Pages) Asahi Kasei Microsystems – DSP with Mono ADC Stereo CODEC + Mic/Lineout Amp

[AK7755]
4. Analog Output
The analog line-outputs are single-ended. The output signal range is 0.76 × AVDD Vpp (typ.) centered
around VCOM voltage. The input code format is in 2’s complement. The output voltage is a positive full
scale for 7FFFFFH (@24bit) and a negative full scale for 800000H (@24bit). The ideal voltage at 000000H
is VCOM. The VCOM voltage is AVDD/2 (typ). The internal switched-capacitor filter (SCF) and
continuous-time filter (CTF) attenuate the noise generated by the delta-sigma modulator beyond the audio
passband.
5. Connection to Digital Circuit
To minimize the noise from digital circuits, the digital output of the AK7755 must be connected to CMOS
or low voltage logic ICs such as 74HC and 74AC for CMOS and 74LV, 74LV-A, 74ALVC and 74AVC for
low voltage logic ICs.
6. Cristal Oscillator
The resistor and capacitor values for the oscillator RC circuit are shown blow.
TVDD = 3.0 - 3.6V
CKM mode
XTAL
Oscillator
0
12.288MHz
1
18.432MHz
R1_max
120Ω
80Ω
C0_max
2.5pF
2.5pF
XTI, XTO pin
Connection Capacity
22pF
15pF
TVDD = 1.7 - 3.0V
CKM mode
XTAL
Oscillator
0
12.288MHz
1
18.432MHz
R1_max
50Ω
25Ω
C0_max
1.2pF
1.2pF
XTI, XTO pin
Connection Capacity
10pF
10pF
Table 15. Crystal Oscillator
014006643-E-00
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2014/10