AD1885
NOTE: LOCATE R1 AND C1 CLOSETO CODEC.
JACK SENSE
D1
MMBD914
TO CODEC JS1 (PIN 48)
OPTIONAL EMC
COMPONENTS
L1 600Z
C4
FROM CODEC HP_OUT_R (PIN 41)
FROM CODEC HP_OUT_L (PIN 39)
+
+
J1
1
2
3
4
5
470pF
L2 600Z
C5
470pF
HEADPHONE OUT
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.
VOLTAGE DIVIDER
AC-COUPLING
TO CODEC CD_L INPUT
1
2
3
4
HEADER FOR
CD ROM AUDIO
(LGGR)
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.
EMC
COMPONENTS
AC-COUPLING
VOLTAGE DIVIDER
LINE/AUX/VIDEO INPUT
L2 600Z
C1
J1
TO CODEC RIGHT CHANNEL INPUT
TO CODEC LEFT CHANNEL INPUT
1
2
3
4
5
470pF
L1 600Z
C2
470pF
Figure 13. LINE_IN, AUX, and Video Input Connections
–24–
REV. 0
ADI [ ADI ]
