CS4397

DS333PP1

21

Common Mode Voltage - CMOUT

Pin 25, Output

Function:

Filter connection for internal bias voltage, typically 50% of VREF. Capacitors must be connected from

CMOUT to analog ground, as shown in Figure 6. CMOUT has a typical source impedence of 25 k

Ω and

any current drawn from this pin will alter device performance

Reference Ground - FILT-

Pin 26, Input

Function:

Ground reference for the internal sampling circuits. Must be connected to analog ground.

Reference Filter - FILT+

Pin 27, Output

Function:

Positive reference for internal sampling circuits. External capacitors are required from FILT+ to analog

ground, as shown in Figure 6. The recommended values will typically provide 60 dB of PSRR at 1 kHz

and 40 dB of PSRR at 120 Hz. FILT+ is not intended to supply external current.

Voltage Reference Input- VREF

Pin 28, Input

Function:

Analog voltage reference. Typically 5VDC.

HARDWARE MODE

Mode Select - M0, M1, M2, M3, M4

Pins 2, 3, 4, 5 and 14, Inputs

Function:

The Mode Select pins determine the operational mode of the device as detailed in Tables 9-14. The op-

tions include;

Selection of the Digital Interface Format which determines the required relationship between the

Left/Right clock, serial clock and serial data as detailed in Figures 29-33

Selection of the standard 15

µs/50 µs digital de-emphasis filter response, Figure 28, which requires re-

configuration of the digital filter to maintain the proper filter response for 32, 44.1 or 48 kHz sample rates.

Selection of the appropriate clocking mode to match the input sample rates.

Access to the Direct Stream Digital Mode

Access to the 8x Interpolation Input Mode

CONTROL PORT MODE

Address Bit 0 / Chip Select - AD0 / CS

Pin 2, Input

Function:

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.