AK7755EN_16 Datasheet, PDF (84/109 Pages) Asahi Kasei Microsystems – DSP with Mono ADC Stereo CODEC + Mic/Lineout Amp

[AK7755]
■ Analog Input Block
1. Microphone Input Selector
Either analog input or digital microphone interface can be chosen for the AK7755. Set AINE bit
(CONT00: D3) to “1” when using #31-34 pins as analog input pins, and set DMIC1(CONT1E: D7) or
DMIC2 bit (CONT1E: D4) to “1” when using these pins as digital microphone interface. ADC input
signals can be switched by DIFL bit (CONT09: D5), DIFR bit (CONT09: D7), INL bit (CONT09: D4)
and INTR bit (CONT09: D6) for analog inputs. When DIFL bit = “0” and DIFR bit = “0”, input signals
of IN1, IN2, IN3 and IN4 pins for microphone amplifiers can be selected by INL and INR bits. When
DIFL bit = “1” and DIFR bit = “1”, a differential input is acceptable as input pins becomes INP1/INN1
pins and INP2/INN2 pins.
IN1/INP1/DMDAT1 pin
IN2/INN1/DMCLK1 pin
INL bit
AK7755
DIFL bit
MIC-Amp
Lch
ADC
Lch
IN3/INP2/DMDAT2 pin
IN4/INN2/DMCLK2 pin
INR bit
DIFR bit
MIC-Amp
Rch
ADC
Rch
Figure 70. Microphone Input Selector
ADC Lch Microphone Input Selector
DIFL bit INL bit ADC Lch
0
0
IN1
0
1
IN2
1
X
INP1/INN1
(x: Do not care)
ADC Rch Microphone Input Selector
DIFR bit INR bit ADC Rch
(default) 0
0
IN3 (default)
0
1
IN4
1
X INP2/INN2
(x: Do not care)
014006643-E-00
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2014/10