CS8421-CNZR Cirrus Logic Inc, CS8421-CNZR Datasheet - Page 24

• Manufacturer Part Number: CS8421-CNZR
• Description: IC,Digital Audio Sample Rate Converter,CMOS,LLCC,20PIN
• Manufacturer: Cirrus Logic Inc

24
4.5
4.6
OLRCK
Output
Source
OLRCK
Clock
PCM Source 1
PCM Source 1
OSCLK
OSCLK
Reset, Power-Down, and Start-Up
When RST is low, the CS8421 enters a low-power mode, all internal states are reset, and the outputs are
disabled. After RST transitions from low to high, the part senses the resistor value on the configuration pins
(MS_SEL, SAIF, and SAOF) and sets the appropriate mode of operation. After the mode has been set (ap-
proximately 4 µ s), the part is set to normal operation and all outputs are functional.
Power Supply, Grounding, and PCB Layout
The CS8421 operates from a VD = +2.5 V and VL = +3.3 V or +5.0 V supply. These supplies may be set
independently. Follow normal supply decoupling practices; see
Extensive use of power and ground planes, ground-plane fill in unused areas, and surface-mount decou-
pling capacitors are recommended. Decoupling capacitors should be mounted on the same side of the
board as the CS8421 to minimize inductance effects, and all decoupling capacitors should be as close to
the CS8421 as possible. The pin of the configuration resistors not connected to MS_SEL, SAIF, and SAOF
should be connected as close as possible to VL or GND.
LRCK
SCLK
SDOUT
SDOUT
TDM_IN
ILRCK
ISCLK
SDIN
TDM_IN
ILRCK
ISCLK
SDIN
Figure 14. TDM Mode Configuration (First CS8421 Output is Master, All Others are Slave)
CS8421
CS8421
Master
Slave
SDOUT
OLRCK
OSCLK
OLRCK
SDOUT
OSCLK
1
1
Figure 13. TDM Mode Configuration (All CS8421 Outputs are Slave)
OLRCK
OLRCK
PCM Source 2
PCM Source 2
OSCLK
OSCLK
SDOUT
SDOUT
TDM_IN
ILRCK
ISCLK
SDIN
TDM_IN
ILRCK
ISCLK
SDIN
CS8421
CS8421
Slave
Slave
SDOUT
OLRCK
OSCLK
2
SDOUT
OLRCK
OSCLK
2
OLRCK
OLRCK
PCM Source 3
PCM Source 3
OSCLK
OSCLK
SDOUT
SDOUT
TDM_IN
ILRCK
ISCLK
SDIN
TDM_IN
ILRCK
ISCLK
SDIN
CS8421
CS8421
Slave
Slave
OLRCK
SDOUT
OSCLK
3
SDOUT
OLRCK
OSCLK
3
OLRCK
Figure
PCM Source 4
OLRCK
PCM Source 4
OSCLK
OSCLK
6.
SDOUT
SDOUT
TDM_IN
ILRCK
ISCLK
SDIN
TDM_IN
ILRCK
ISCLK
SDIN
CS8421
CS8421
Slave
Slave
SDOUT
OLRCK
OSCLK
4
SDOUT
OLRCK
OSCLK
4
CS8421
DS641F1
LRCK
SCLK
SDIN
LRCK
SCLK
SDIN
DSP
Slave
DSP
Slave