DS749RD1

7

CRD4412

switching outputs in the 30-50 MHz range. The snubbing components should be as close as practical

to the output pins to maximize their effectiveness.

• A separate ground plane with a solid electrical connection to the chassis and which surrounds the

speaker output connector should be implemented. This allows the speaker outputs to be RF decoupled

to the chassis just before they exit the chassis from the speaker connector.

• Make use of source termination resistors on all digital signals whose traces are longer than about

25 mm.

It is extremely critical that the layout of the power amplifier section of the CRD4412 be copied as exactly

as possible to assure best RF/EMI performance.

4. SYSTEM CONNECTIONS AND JUMPERS

Connector

Name

Reference

Designator

Signal

Direction

Connector Function

Speaker

Connector

J5

Output

Analog output from CS4525.

Table 1. System Connections

Connector Name

Reference

Designator

Header Function

CRD4412 I/F

J2

Connection to CRD4525 controller card.

-

J1

Selects between mono and stereo PWM input mode.

-J4

Connects CS4412 thermal warning output to CRD4412 interface header.

Allows direct access to CS4412 TWR and CS4525 DLY_SDIN signals when

CRD4525 is connected.

-J6

Allows direct access to CS4412 ERROC12/34 and CS4525 DLY_SDOUT

signals when CRD4525 is connected.

Table 2. System Headers

Pin

Signal Name

Signal Function

1

SDA

I²C serial data.

2

+3.3 V

Positive VD power.

3

SCL

I²C serial clock.

4

DLY_SDIN/TWR

CS4525 delay port serial audio data input/CS4412 thermal warning output.

5

ERROC1234

CS4412 over-current error outputs.

6

DLY_SDOUT

CS4525 delay port serial audio data output.

7, 9, 11, 13, 15, 16

GND

Ground reference.

8

PWM_SIG1

Left channel logic level PWM input.

10

PWM_SIG2

Right channel/mono logic level PWM input.

12

ERRUVTE

CS4412 under-voltage/temperature error output.

14

RST

CS4412 reset input.

17, 18, 19, 20

+9 V to +18 V

High voltage VP power.

Table 3. CRD4412 Interface Header Signal Assignments