MC13783VKR2 Datasheet, PDF (27/50 Pages) Freescale Semiconductor, Inc – Power Management and Audio Circuit

Functional Description
DAC will operate in its assigned time slot. A total of maximum 4 time slot pairs are supported depending
on the settings of the clock speed. In this case, the sync signal is no longer a word select but a short frame
sync. In all modes, the polarity of both FS and BCL is programmable by SPI. There is also the possibility
to activate the clocking circuitry independent from the stereo DAC.
4.3.1.4 Audio Port Mixing
In network mode, the receive data from two right channel time slots and of two left channel time slots can
be added. One left/right time slot pair is considered to represent the main audio flow whereas the other
time slot pair represents the secondary flow. The secondary flow can be attenuated with respect to the main
flow by 0 dB, 6 dB and 12 dB which should be sufficient to avoid clipping of the composite signal. In
addition, the composite signal can be attenuated with 0 dB or 6 dB.
4.3.2 Voice CODEC
4.3.2.1 A/D Converters
The A/D portion of the voice CODEC consists of two A/D converters which convert two incoming analog
audio signals into 13-bit linear PCM words at a rate of 8 kHz or 16 kHz. Following the A/D conversion,
the audio signal is digitally band pass filtered. The converted voice is available on the audio bus. If both
A/D channels are active, the audio bus is operated in a network mode.
Table 12. Telephone CODEC A/D Performance Specifications
Parameter
Condition
Min
Typ
Max
Units
Peak Input (+3 dBm0) single ended
REFC-0.68
REFC+0.68
V
CODEC PSRR
with respect to BP,
0 to 20 kHz
80
90
—
dB_P
Total Distortion (noise at 1.02 kHz (linear) 0 dBm0
and harmonic)
8.0 kHz measurement BW out
60
70
—
dB_P
Idle Channel Noise
0 db PGA gain
incl. microphone amp
—
—
-72
dBm0_P
Inband Spurious
0 dBm0 at 1.02 kHz input,
—
—
-48
dB
300 Hz to 3.0 kHz (8 kHz sample rate)
4.3.2.2 D/A Converter
The D/A portion of the voice CODEC converts 13-bit linear PCM words entering at a rate of 8 kHz and
16 kHz into analog audio signals. Prior to this D/A conversion, the audio signal is digitally band-pass
filtered.
MC13783 Technical Data, Rev. 3.5
Freescale Semiconductor
27