Cirrus Logic CDB6422 - Manual (Page 5)

CDB6422
DS295DB2 5
+20dB". The pot labeled "AIN_GAIN" (R2) con-
trols the variable gain.
2.2.1.5 AIN5:
AIN5 selects the acoustic input source from the fol-
lowing options: “ACTIVE” (the previous gain
sources), “PASSIVE” (the RC-network), and “DT-
MF” (the DTMF transceiver, used for testing pur-
poses).
2.2.1.6 AIN6, AIN7:
AIN6 and AIN7 are configured based on the state
of the internal MIC preamp on the CS6422. If the
internal mic preamp is enabled (Mic = '1'), then
AIN6 and AIN7 should be configured to the "ON"
position. If the internal mic preamp is disabled
(Mic = '0'), then AIN6 and AIN7 should be config-
ured to the "OFF" position.
2.2.2 Acoustic Output
2.2.2.1 AOUT1:
AOUT1 selects between the “ACTIVE” drive out-
put circuitry (op-amps) and the “PASSIVE” cir-
cuitry (simple RC-network). To take advantage of
the supplied filters and gain stages, set AOUT1 to
the “ACTIVE” state.
2.2.2.2 AOUT2:
AOUT2 selects the order of the Butterworth filter
following AO at either "1-POLE" or "3-POLES".
2.2.2.3 AOUT3, AOUT4:
AOUT3 and AOUT4 select the type and amount of
gain for the acoustic output circuitry. For fixed
gains (AOUT4 = “0dB” or “USER”), AOUT3
should be set to "FIXED". For variable gain (-
20dB to +20dB) AOUT3 should be set to "VARI-
ABLE" and AOUT4 should be set to "-20dB to
+20dB". The pot labeled "AOUT_GAIN" (R3)
controls the variable gain.
2.2.2.4 AOUT5:
AOUT5 selects the source of the acoustic output
RCA jack (“0dB” before gain stage, “GAINED”
after gain stage, or “PASSIVE” RC-network).
2.2.2.5 AOUT6:
AOUT6 selects the type of output (“AC”-coupled
or ”DC”-coupled) at the AOUT_RCA jack.
2.2.2.6 SPEAKER_GAIN:
SPEAKER_GAIN selects the gain of the on-board
differential BTL speaker driver to “0dB”, “+6dB”,
“+9dB”, or “USER”. The “+9dB” setting should
not be used, as it will result in clipping at the speak-
er driver outputs.
2.2.3 Network Input
2.2.3.1 NIN1:
NIN1 selects between the “ACTIVE” network in-
put circuitry (op-amps) and a “PASSIVE” RC-net-
work.
2.2.3.2 NIN2, NIN3:
NIN2 and NIN3 select the type and amount of gain
for the network input circuitry. For fixed gains
(NIN3 = “0dB” or ”USER”), NIN2 should be set to
"FIXED". For variable gain (-20dB to +20dB)
NIN2 should be set to "VARIABLE" and NIN3
should be set to "-20dB to +20dB". The pot labeled
"NIN_GAIN" (R5) controls the variable gain.
2.2.3.3 NIN4:
NIN4 selects the network input source from the fol-
lowing options: “ACTIVE” (the previous gain
sources), “PASSIVE” (the RC-network),
“POTS(DAA)” (the analog telephone line), “CO-
DEC” (the
µ-law codec), or “DTMF” (the DTMF
transceiver, used for testing purposes).