CS8406-CSZ datasheet(33/42 Pages) CIRRUS

33 / 42 page

DS580F5

CS8406

12.APPLICATIONS

12.1

Reset, Power Down and Start-Up

When RST is low, the CS8406 enters a low power mode and all internal states are reset, including the con-

trol port and registers, and the outputs are disabled. In Software Mode when RST is high, the control port

becomes operational and the desired settings should be loaded into the control registers. Writing a 1 to the

RUN bit will then cause the part to leave the low power state and begin operation. In Hardware Mode when

RST is high, the part will automatically leave the low power state and begin operation.

12.2

ID Code and Revision Code

The CS8406 has a register that contains a four-bit code to indicate that the addressed device is a CS8406.

This is useful when other CS84XX family members are resident in the same or similar systems, allowing

common software modules.

The CS8406 four-bit revision level code is also available. This allows the software driver for the CS8406 to

identify which revision of the device is in a particular system, and modify its behavior accordingly. To allow

for future revisions, it is strongly recommended that the revision code is read into a variable area within the

microcontroller, and used wherever appropriate as revision details become known.

12.3

Power Supply, Grounding, and PCB layout

The CS8406 operates from a VD = +3.3 V or +5.0 V and VL = +3.3 V or +5.0 V supply. These supplied may

be set independently. Follow normal supply decoupling practices, see Figures 5 and 6. The VD and VL sup-

plies should be decoupled with a 0.1

μF capacitor to GND to minimize AES3 transmitter induced transients.

Extensive use of power and ground planes, ground plane fill in unused areas and surface mount decoupling

capacitors are recommended. Decoupling capacitors should be mounted on the same side of the board as

the CS8406 to minimize inductance effects, and all decoupling capacitors should be as close to the CS8406

as possible.

The CS8406 is available in the compact QFN package. The underside of the QFN package reveals a metal

pad; this pad must mate with an equally dimensioned copper pad on the PCB and must be electrically con-

nected to ground. A series of vias should be used to connect this copper pad to one or more ground planes

on other PCB layers.

12.4

Synchronization of Multiple CS8406s

The AES3 transmitters of multiple CS8406s can be synchronized if all devices share the same master clock,

TCBL, and RST signals. The TCBL pin is used to synchronize multiple CS8406 AES3 transmitters at the

channel status block boundaries. One CS8406 must have its TCBL set to master; the others must be set to

slave TCBL. Alternatively, TCBL can be derived from external logic, whereby all CS8406 devices should be

set to slave TCBL.

CS8406-CSZ Arkusz danych(PDF) 33 Page - Cirrus Logic