AK4128A Datasheet, PDF (30/50 Pages) Asahi Kasei Microsystems – 8ch 216kHz / 24-Bit Asynchronous SRC

[AK4128A]
■ 6/4channel Mode
The AK4128A has 6-channel and 4-channel modes to reduce power supply current when not using all eight channels.
When the PM2 and PM1 pins are set to “L/L”, six channels (SDTI1Æ SDTO1, SDTI2 Æ SDTO2 and SDTI3 Æ SDTO3)
are powered-up and the other two channels (SDTI4 Æ SDTO4) are powered-down (“L” output). When the PM2 and PM1
pins are set to “L/H”, four channels (SDTI1Æ SDTO1 and SDTI2 Æ SDTO2) are powered-up and the other four channels
(SDTI3 Æ SDTO3 and SDTI4 Æ SDTO4) are powered-down (“L” output). In 6-channel and 4-channel modes, the X’tal
oscillator circuit and the MCKO output are powered-down and the XTO pin and MCKO pin output Hi-z.
PM2 PM1 PDN
pin pin pin
L LL
L LH
L HL
L HH
H LL
H LH
H HL
H HH
Mode
6-channel
mode
4-channel
mode
8-channel
mode
Not
available
X’tal Oscillator
XTI pin
XTO pin MCKO pin
Power-down ^{Pull down to VSS2-5 (note)} Hi-z
Input
Hi-z
Power-down ^{Pull down to VSS2-5 (note)} Hi-z
Input
Power-down Pull down to VSS2-5 (note) Hi-z
L
Normal operation
Input
Output Normal operation
-
-
-
-
-
-
-
-
Note: Pull down (460kΩ typ.) to VSS2-5.
Table 8. Channel Mode Setting
■ Soft Mute Operation
1. Manual Mode
The soft mute operation is performed in the digital domain of the SRC output. SRC1-4 soft mutes are controlled together by
the SMUTE pin in parallel control mode (SPB pin = “L”). In serial control mode (SPB pin = “H”), setting of the SMUTE
pin is ignored. SRC1 reflects SMUTE1 bit setting, SRC2 reflects SMUTE2 bit setting, SRC3 reflects SMUTE3 bit setting,
and SRC4 reflects SMUTE4 bit setting.
When the SMUTE pin goes “H” or SMUTE1-4 bits becomes “1”, all the outputs data are attenuated by −∞ during 1024
OLRCK cycles (@ SMT1 pin = “L” and SMT0 pin = “L”). When the SMUTE pin goes “L” or SMUTE1-4 bits becomes
“0”the mute is cancelled and the output attenuation gradually changes to 0dB during 1024 OLRCK cycles (@ SMT1 pin =
“L” and SMT0 pin = “L”). If the soft mute is cancelled before attenuating to -∞, the attenuation is discontinued and
returned to 0dB by the same cycles. The soft mute is effective for changing the signal source without stopping the signal
transmission. Soft mute cycle is set by SMT1-0 pins. SMT1-0 pins must not be changed during soft mute transition.
SMT1pin
L
L
H
H
SMT0 pin
Period FSO=48kHz FSO=96kHz
L
1024/fso
21.3ms
10.7ms
H
2048/fso
42.7ms
21.3ms
L
4096/fso
85.3ms
42.7ms
H
8192/fso
170.7ms
85.3ms
Table 9. Soft Mute Cycle Setting (Parallel Mode)
FSO=192kHz
5.3ms
10.7ms
21.3ms
42.7ms
MS1242-E-00
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2010/09