AD1885

–24–

REV. 0

L1 600Z

L2 600Z

C4

470pF

OPTIONAL EMC

COMPONENTS

+

+

NOTE: LOCATE R1 AND C1 CLOSE TO CODEC.

JACK SENSE

TO CODEC JS1 (PIN 48)

FROM CODEC HP_OUT_R (PIN 41)

FROM CODEC HP_OUT_L (PIN 39)

HEADPHONE OUT

1

2

3

4

5

J1

C5

470pF

D1

MMBD914

Figure 11. Jack Sense Connection to HP_OUT Jack, Using Nonisolated Switch

LINE_ OUT Jack

Although not shown, if a LINE_OUT jack is used and the jack sense functionality is desired, the LINE_OUT jack should be wired

in a similar configuration as shown above for the HP_OUT jack (preferably Figure 10). The LINE_OUT jack should normally

be connected to the JS0 input, in order to mute the MONO_OUT signal. We recommend that in this case the output coupling

caps (C2, C3) be set to 2.2

µF. All other values should be kept the same.

APPLICATION CIRCUITS

CD-ROM CONNECTIONS

Typical CD-ROM drives generate 2 V rms output and require a voltage divider for compatibility with the Codec input (1 V rms

range). The recommended circuit is basically a group of divide-by-two voltage dividers as shown on Figure 12.

The CD_GND_REF pin is used to cancel differential ground noise from the CD-ROM. For optimum noise cancellation, this sec-

tion of the divider should have approximately half the impedance of the right and left channel section dividers.

1

2

3

4

HEADER FOR

CD ROM AUDIO

(LGGR)

VOLTAGE DIVIDER

AC-COUPLING

TO CODEC CD_L INPUT

TO CODEC CD_GND_REF INPUT

TO CODEC CD_R INPUT

Figure 12. Typical CD-ROM Audio Connections

LINE_IN, AUX AND VIDEO INPUT CONNECTIONS

Most of these audio sources also generate 2 V rms audio level and require a –6 dB input voltage divider to be compatible with the

Codec inputs. Figure 13 shows the recommended application circuit. For applications requiring EMC compliance, the EMC com-

ponents should be configured and selected to provide adequate RF immunity and emissions control.

VOLTAGE DIVIDER

AC-COUPLING

TO CODEC RIGHT CHANNEL INPUT

TO CODEC LEFT CHANNEL INPUT

LINE/AUX/VIDEO INPUT

1

2

3

4

5

J1

EMC

COMPONENTS

C1

470pF

C2

470pF

L2 600Z

L1 600Z

Figure 13. LINE_IN, AUX, and Video Input Connections