Specifications

Audio Interface
Rev 2.0 Apr.10 Proprietary and Confidential 51
Figure 4-3: MC8775V /MC8790V/MC8791V/MC8792V/MC8795V Audio system block
Modes of operation
These modules support the following operational modes: headset, handset, car
kit, speakerphone, AUX
1
, and TTY—end products can use any combination of
these modes.
The host device must use host-modem messaging to tell the module which mode
to use for each call.
Sidetone support
The sidetone path mixes the near-end transmit voice to the near-end receive.
This gives the near-end user some feedback that indicates that the call is up and
that the audio system is functioning.
The sidetone path can be enabled in either the PDA codec or the embedded
module—each path is equally valid. It should not be added to both devices, and
for speakerphone or car kit applications, both sidetone paths should be disabled.
The typical handset sidetone is 12 dB below transmit voice levels.
Decoder
RX DAC
EncoderTX ADC
HPF &
Slope
HPF
Echo Cancellation
NS &
AAGC
Tx FIR
Rx FIR
13K CELP/
EVRC
Decoder
AAGC
13 bit A/D
13 bit D/A
CodecRxGain
RX_HPF_DIS_N
CodecSTGain
CodecTxGain
TX_HPF_DIS_N
TX_SLOPE_FILT_DIS_N
MIC_AMP1_GAIN
-6dB to +49.5dB
in 1.5dB steps
nsSwitch TxPCMFilt
TxVolume
RxVolume
RxPCMFilt
AMP_SEL
001 010 100
35mW @ +3dBm0
RF Filter
33n
22p
PCM I/F
+12dB
-25dB
-84dB
+12dB
-3dB
-84dB
+12dB
0dB
-81dB
+12dB
-48dB
-96dB
+12dB
0dB
-84dB
57.3mVrms
@ 0dBm0
SPK_P
SPK_N
MIC_P
MIC_N
13K CELP/
EVRC
Encoder
DTMF
Encoder
DTMF Rx Gain
DTMF Tx Gain
DTMF
Decoder
Audio In
Audio Out
RF
Interface
PCM Audio interface
1. MC5727V/MC5728V modules are preconfigured for HAC [Hearing Aid Compatibil-
ity].