EVAL-AD1937AZ Analog Devices Inc, EVAL-AD1937AZ Datasheet - Page 20

• Manufacturer Part Number: EVAL-AD1937AZ
• Description: EB Single Chip Codec 4 ADCs W/Diff Outp
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD1937AZ

• Main Purpose: Audio, CODEC
• Utilized Ic / Part: AD1937
• Primary Attributes: 24-Bit, 192 kHz, 4 ADCs: 107dB Dynamic Range, 8 DACs: 112dB Dynamic Range
• Secondary Attributes: Time Division Multiplexed (TDM), I2C, and SPI Interface, Popguard® Technology
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Embedded: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD1937
TIME-DIVISION MULTIPLEXED (TDM) MODES
The serial ports of the AD1937 have several different TDM
serial data modes. Single-line TDM mode is the most com-
monly used configuration (see Figure 16 and Figure 17).
These figures show 8-channel configuration; other possible
options are 4- and 16-channel configurations. In Figure 16,
the eight on-chip DAC data slots are packed into one I
TDM stream. In this mode, both DBCLK and ABCLK are
256 f
stream consisting of four on-chip ADCs followed by four
unused slots.
DLRCLK
DSDATA
ASDATA
Table 18. Pin Function Changes in TDM and TDM/AUX Modes
Mnemonic
ASDATA1
ASDATA2
DSDATA1
DSDATA2
DSDATA3
DSDATA4
ALRCLK
ABCLK
DLRCLK
DBCLK
ALRCLK
DBCLK
ABCLK
S
. In Figure 17, the ADC serial port outputs one data
Figure 16. Single-Line TDM Mode 8-Channel DAC Configuration
Figure 17. Single-Line TDM Mode 8-Channel ADC Configuration
32 BCLKs
SLOT 1
LEFT 1
32 BCLKs
SLOT 1
LEFT 1
RIGHT 1
RIGHT 1
SLOT 2
SLOT 2
MSB
Stereo Modes
ADC1 data out
ADC2 data out
DAC1 data in
DAC2 data in
DAC3 data in
DAC4 data in
ADC LRCLK in/out
ADC BCLK in/out
DAC LRCLK in/out
DAC BCLK in/out
MSB
SLOT 3
LEFT 2
SLOT 3
LEFT 2
MSB – 1
MSB – 1
RIGHT 2
RIGHT 2
SLOT 4
SLOT 4
256 BCLKs
256 BCLKs
MSB – 2
MSB – 2
SLOT 5
LEFT 3
SLOT 5 SLOT 6 SLOT 7 SLOT 8
LRCLK
BCLK
DATA
LRCLK
BCLK
DATA
RIGHT 3
SLOT 6
TDM Modes
TDM ADC data out
TDM ADC data in
TDM DAC data in
TDM DAC data out
TDM DAC2 data in (dual-line mode)
TDM DAC2 data out (dual-line mode)
TDM ADC frame sync in/out
TDM ADC BCLK in/out
TDM DAC frame sync in/out
TDM DAC BCLK in/out
SLOT 7
LEFT 4
2
S
RIGHT 4
SLOT 8
Rev. B | Page 20 of 36
The I/O pin functions of the serial ports are defined according
to the serial mode that is selected. For a detailed description of
the function of each pin in TDM and TDM/AUX modes, see
Table 18.
The AD1937 allows systems with more than eight DAC channels
to be easily configured by the use of an auxiliary serial data port.
The TDM/AUX mode 16-channel configuration is shown in
Figure 18. In this mode, the AUX channels are the last four
slots of the TDM data stream. These slots are extracted and
output to the AUX serial port. It should be noted that due to
the high DBCLK frequency, this mode is available only in the
48 kHz/44.1 kHz/32 kHz sample rates. An 8-channel DAC
configuration cannot be TDM/AUX because there are no
extra data slots for the AUX packets; this would be single-
line TDM mode.
The AD1937 also allows system configurations with more
than four ADC channels as shown in Figure 19 (using 8 ADCs)
and Figure 20 (using 16 ADCs). Due to the high ABCLK
frequency, this mode is available only in the 48 kHz/44.1 kHz/
32 kHz sample rates.
Combining the TDM/AUX ADC and DAC modes results in
a system configuration of 8 ADCs and 12 DACs. The system,
then consists of two external stereo ADCs, two external stereo
DACs, and one AD1937. This mode is shown in Figure 21
(combined TDM/AUX DAC and ADC modes).
In the TDM/AUX mode, the frame sync (ALRCLK) triggers
the TDM word by crossing the high frequency TDM BCLK
(ABCLK) to 0, similar to the single-line TDM modes (see
Figure 16 and Figure 17). The AUX LRCLK (DLRCLK) runs at
the much slower f
runs at 64 × f
Figure 18 to Figure 21).
S
. This is shown in the TDM/AUX figures (see
S
of the AUX port; the AUX BCLK (DBCLK)
AUX DAC1 data out (to external DAC1)
AUX LRCLK in/out
TDM/AUX Modes
TDM data out
TDM data in
AUX ADC1 data in (from external ADC1)
AUX ADC2 data in (from external ADC2)
AUX DAC2 data out (to external DAC2)
TDM frame sync in/out
TDM BCLK in/out
AUX BCLK in/out