AK7735EQ Datasheet, PDF (95/142 Pages) Asahi Kasei Microsystems – Dual DSP with 4chADC + 4chDAC + 4chSRC

[AK7735]
1-3. Start-up Time of MIC Input Pin
The AK7735 starts to charge a DC cut capacitor when the PDN pin is set to “H” from “L”. Since the input
impedance is 25kΩ, the time constant will be 25ms if the DC cut capacitor is 1µF. A wait time of about
100ms should be taken before power up the ADC to charge the DC cut capacitor sufficiently. A click
noise may occur just after the ADC is powered up if this wait time is not enough.
2. Microphone Input Selector
The AK7735 has microphone input selectors. Each microphone amplifier input is selectable between
single-ended input and differential input by AD1LSEL bit or AD1RSEL bit.
AIN1L / INP1 pin
INN1 pin
AIN1R / INP2 pin
INN2 pin
AD1LSEL bit
AK7735
MIC-Amp Lch
ADC Lch
AD1RSEL bit
MIC-Amp Rch
ADC Rch
Figure 70. Microphone Input Selector
AD1LSEL bit
ADC Lch
AD1RSEL bit ADC Rch
0
INP1/INN1 (default)
0
INP2/INN2 (default)
1
AIN1L
1
AIN1R
Table 47. Microphone Input Selector
Note
* 79. When using differential input mode, it is prohibited to input signal to only one side like pseudo
differential input.
016014707-E-00
- 95 -
2016/12