MT92303 Zarlink Semiconductor, MT92303 Datasheet - Page 4

• Manufacturer Part Number: MT92303
• Manufacturer: Zarlink Semiconductor

MT92303
Functional Description
The MT92303 Dual Codec provides complete audio
to PCM interfaces including filtering and optional
data companding as required by the ITU-T G.711 &
G.712 recommendations. Programmable gain allows
adjustment
sensitivities - two microphone amplifiers and four
earpiece amplifiers are provided to allow connection
to a handset, headset, auxiliary channel and
microphone/speaker. A cross-point circuit allows
4
4
4
Serial PCM
Interface
Voice
Serial
uPort
Data
Data
Data
Data
for
a
Status
Control for companding mode, RX gain control(s),
sidetone level, RX hi-pass filter, cross-point, muting,
electret biasing, microphone pre-amp and gain, PLL
Law
Law
Law
Law
u/A
u/A
u/A
u/A
wide
SYSCLK
Sidetone
Sidetone
PLL
range
of
Codec #1
Codec #0
RESETB
transducer
Figure 3 - Block Diagram
Filtering
Filtering
G.712
G.712
VREF
VREF
either Codec to be connected to any of the four
Audio Interfaces. Programmable voltage sources are
available for electret biasing on the Microphone
channels.
PCM voice data is passed via a serial interface which
operates in ST-bus, GCI or SSI mode. ST-bus mode
allows the Codecs to be allocated to any of the 32
available channels. Control and programming of the
Codecs is carried out over a flexible, serial,
micro-controller interface.
D
C
D
C
A
A
AUXTONE
D
C
D
C
A
A
Cross-Point
Preliminary Information
Electret
Detect
Electret
Detect
Electret
Mic
Mic
Bias
Bias
Bias