AK4371 Datasheet, PDF (37/62 Pages) Asahi Kasei Microsystems – DAC with built-in PLL & HP-AMP

[AK4371]
■ Mono Hands-free Output (MOUT pin)
The common voltage is 0.475 x AVDD. The load resistance is 600Ω(min). When the PMMO bit is “1”, the mono
Hands-free output is powered-up. DALM, DARM, LIN1M, RIN1M, LIN2M, RIN2M, LIN3M and RIN3M bits control
each path switch. When MOG bit = “0”(R_DM=100k) and ATTM3-0 bits = “0FH”(0dB), the mixing gain is −6dB(typ) for
all paths. When MOG bit = “1”(R_DM=50k) and ATTM3-0 bits = “0FH”(0dB), the mixing gain of output signal is 0dB.
When LDIF=LDIFM=LIN1L=RIN1R bits = “1”, LIN1 and RIN1 pins become IN− and IN+ pins respectively. IN− and
IN+ pins can be used as full-differential mono line input for analog mixing of MOUT pin. In this case, LIN1M and
RIN1M bits should be “0”.
If the path is OFF and the signal is input to the input pin, the input pin should be biased to a voltage equivalent to VCOM
voltage (= 0.475 x AVDD) externally. Figure 46 shows the external bias circuit example.
Figure 27
LIN1 pin
RIN1 pin
LIN2 pin
RIN2 pin
LIN3 pin
RIN3 pin
DAC Lch
DAC Rch
100k(typ)
LDIFM bit
100k(typ)
LIN1M bit
100k(typ)
RIN1M bit
100k(typ)
LIN2M bit
100k(typ)
RIN2M bit
100k(typ)
LIN3M bit
100k(typ)
50k(typ)
RIN3M bit
RDM
DALM bit
RDM
RM
−
RM
−
+
+
DARM bit
Figure 28. Summation circuit for Mono Hands-free output
MOUT pin
■ Mono Hands-free Output (MOUT pin) Volume
MOUT volume is controlled by ATTM3-0 bit when MMUTE bit = “0” (+6dB ∼ −24dB or 0dB ∼ −30dB, 2dB step, Table
27). Pop noise occurs when ATTM3-0 bits are changed.
MMUTE
0
1
ATTM3-0
MOG bit = “1”
(DAC Only)
MOG bit = “0”
FH
+6dB
0dB
EH
+4dB
−2dB
DH
+2dB
−4dB
CH
0dB
−6dB
:
:
:
:
:
:
1H
−22dB
−28dB
0H
−24dB
−30dB
x
MUTE
MUTE
Table 27. MOUT Volume ATT values (x: Don’t care)
(default)
MS0596-E-00
- 37 -
2007/04