AK5558VN_16 Datasheet, PDF (46/70 Pages) Asahi Kasei Microsystems – 8-Channel Differential 32-bit ADC

[AK5558]
■ Channel Summation (PCM Mode, DSD Mode)
Channel Summation function improves the dynamic range and S/N performance by averaging all A/D
data of multiple-channel that the same signal is input. The AK5558 supports 8-to-4 mode, 8-to-2 mode,
8-to-1mode.
8-to-4 mode (2-Stereo mode)
Improve the dynamic range and S/N for 3 dB (2 dB in DSD mode) by averaging two channels.
8-to-2 mode (Stereo mode)
Improve the dynamic range and S/N for 6 dB (4 dB in DSD mode) by averaging four channels.
8-to-1 mode (Mono mode)
Improve the dynamic range and S/N for 9 dB (6 dB in DSD mode) by averaging eight channels.
Not-Summation mode (4-Stereo mode)
Normal mode that does not execute Summation is called as Not-Summation mode or 4-Stereo mode.
Refer to the section “CH Power Down & Channel Summation mode” for details.
■ Optimal Data Placement (PCM Mode, DSD Mode)
Assigned data to the SDTO1-4 slot is controlled by the ODP pin setting in parallel control mode.
When the ODP pin = “L”, the data is output by Fixed Data Placement mode. Channel assignment of data
slot is fixed regardless of enable/disenable of channel summation. For example, averaging data of two
channels are output to both channel slots.
When the ODP pin = “H”, the data is output by Optimal Data Placement mode that is uses data slot more
efficiently. In Optimal Data Placement mode, there are no data redundant of channel summation, and the
data is output in MSB justified. Therefore, the maximum number of connecting device in cascade
connection will be increased.
If the AK5558 is set to 8-to-4 mode (2-Stereo Mode), two devices can be connected in TDM256 mode,
four devices can be connected in TDM512 mode.
If the AK5558 is set to 8-to-2 mode (Stereo Mode), two devices can be connected in TDM128 mode, four
devices can be connected in TDM256 mode and eight devices can be connected in TDM512 mode.
If the AK5558 is set to 8-to-1 mode (Mono Mode), four devices can be connected in TDM128 mode, eight
devices can be connected in TDM256 mode and sixteen devices can be connected in TDM512 mode.
In serial control mode, the data output is Optimal Data Placement mode regardless of the ODP pin
setting.
Refer to “CH Power Down & Channel Summation mode” for details.
015099850-E-00
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2016/03