AK5554 Datasheet, PDF (37/68 Pages) Asahi Kasei Microsystems – 4-Channel Differential 32-bit ADC

[AK5554]
Cascade Connection in TDM mode
The AK5554 supports cascade connection in TDM mode. All A/D converted data of connected AK5554
are output from the SDTO1 pin of the last AK5554 by cascade connection.
When the ODP pin = “L”, a cascade connection of one devices in TDM128 mode, two devices in TDM256
mode and four devices in TDM512 mode are supported. Figure 29 shows a connection example. When
the ODP pin = “H”, a cascade connection of two up to sixteen devices is available.
When using multiple devices in slave mode on cascade connection, internal operation timing of each
device may differ for one MCLK cycle depending on MCLK and BICK input timings. To prevent this timing
difference, BICK “↓” should be more than ± 10ns from MCLK “↑” as shown in Table 10. To realize this
timing, BICK divided by two should be input on a falling edge of MCLK as shown in Figure 54 when
MCLK=2xBICK (normal speed 1024fs mode). When MCLK=BICK (normal speed 512fs mode), MCLK
and BICK should be input in-phase as shown in Figure 55 to satisfy the timing shown in Table 10.
48kHz
256fs
256fs, 512fs or 1024fs
48kHz
512fs
AK5554 #1
MCLK
TDMIN
LRCK
BICK SDTO1
GND
Master mode
AK5554 #1
MCLK
TDMIN
LRCK
BICK SDTO1
GND
AK5554 #2
MCLK
TDMIN
LRCK
BICK SDTO1
Slave mode
Slave mode
AK5554 #2
MCLK
TDMIN
LRCK
BICK SDTO1
8ch TDM
AK5554 #3
MCLK
TDMIN
LRCK
BICK SDTO1
Slave mode
TDM256
Slave mode
AK5554 #4
MCLK
TDMIN
LRCK
BICK
16ch TDM
SDTO1
Figure 29. Cascade Connection
Slave mode
TDM512
015099864-E-00
- 37 -
2016/03