Cirrus Logic CS4391 - Manual (Page 23)

CS4391
DS335PP4 23
Serial Control Interface Clock - SCL/CCLK (Control Port Mode)
Pin 8, Input
Function:
Clocks the serial control data into or from SDA/CDIN.
Serial Control Data I/O - SDA/CDIN (Control Port Mode)
Pin 9, Input/Output
Function:
In I
2
C mode, SDA is a data I/O line. CDIN is the input data line for the control port interface in SPI mode.
Address Bit / Chip Select - AD0 / CS (Control Port Mode)
Pin 10, Input
Function:
In I
2
C mode, AD0 is a chip address bit. CS is used to enable the control port interface in SPI mode. The
device will enter the SPI mode at anytime a high to low transition is detected on this pin. Once the device
has entered the SPI mode, it will remain until either the part is reset or undergoes a power-down cycle.
Positive Voltage Reference - FILT+
Pin 11, Output
Function:
Positive reference for internal sampling circuits. External capacitors are required from FILT+ to analog
ground, as shown in Figure 5 and 6. The recommended values will typically provide 60 dB of PSRR at
1 kHz and 40 dB of PSRR at 60 Hz. FILT+ is not intended to supply external current. FILT+ has a typical
source impedance of 250 k
Ω and any current drawn from this pin will alter device performance.
Common Mode Voltage - CMOUT
Pin 12, Output
Function:
Filter connection for internal common mode reference voltage, typically 50% of VA. Capacitors must be
connected from CMOUT to analog ground, as shown in Figure 56. CMOUT is not intended to supply
external current. CMOUT has a typical source impedance of 250 k
Ω and any current drawn from this pin
will alter device performance.
Channel A and Channel B Mute Control - AMUTEC and BMUTEC
Pins 13 and 20, Outputs
Function:
The Mute Control pins go high during power-up initialization, reset, muting, master clock to left/right clock
frequency ratio is incorrect or power-down. These pins are intended to be used as a control for an external
mute circuit to prevent the clicks and pops that can occur in any single supply system. Use of Mute Control
is not mandatory but recommended for designs requiring the absolute minimum in extraneous clicks and
pops.