mt9094apr1 Zarlink Semiconductor, mt9094apr1 Datasheet - Page 5

• Manufacturer Part Number: mt9094apr1
• Description: Fully Featured Digital Telephone Circuit With Embedded Dsp For Tone Generation And Hands Free Operation
• Manufacturer: Zarlink Semiconductor

On PWRST (pin 6) the Filter/CODEC defaults such that the side-tone path, dial tone filter and 400 Hz transmit filter
are off, all programmable gains are set to 0 dB and µ-Law companding is selected. Further, the Filter/CODEC is
powered down due to the PuFC bit (Transducer Control Register, address 0Eh) being reset. This bit must be set
high to enable the Filter/CODEC.
The internal architecture is fully differential to provide the best possible noise rejection as well as to allow a wide
dynamic range from a single 5 volt supply design. This fully differential architecture is continued into the Transducer
Interface section to provide full chip realization of these capabilities.
A reference voltage (V
biasing the internal analog sections, are both generated on-chip. V
may be used for biasing any external gain plan setting amplifiers. A 0.1 µF capacitor must be connected from V
to analog ground at all times. Likewise, although V
Note: *gain the same for A-Law and m
SERIAL
PCM
PCM
PORT
DIGITAL DOMAIN
DSP GAIN*
+22.5 dB
Handsfree
Transmit
+22.5 dB
Receive
Ringer &
(1.5dB
–72 to
steps)
DTMF,
(1.5dB
–72 to
steps)
Tone
Internal to Device
Ref
), for the conversion requirements of the CODER section, and a bias voltage (V
−
Law
FILTER/CODEC
µ-Law –11 dB
Α-Law –18.8 dB
(3.32 dB steps)
(1 dB steps)
(1 dB steps)
Filter Gain
0 to –7 dB
Filter Gain
0 to +7dB
Figure 3 - Audio Gain Partitioning
Side-tone
Side-tone
Transmit
Receive
+9.96dB
–9.96 to
Nominal
Gain
Zarlink Semiconductor Inc.
Ref
MT9094
may only be used internally, a 0.1 µF capacitor from the V
5
µ-Law 6.1dB
Α-Law 15.4dB
Speaker Gain
(8 dB steps)
0 to –24 dB
-6 dB
TRANSDUCER INTERFACE
ANALOG DOMAIN
Bias
Transmit
is also brought to an external pin so that it
Gain
µ-Law –6.3 dB
Α-Law –3.7 dB
from DSP)
Receiver
Speaker
0.2dB*
Phone
Ringer
Driver
Driver
(input
Tone
M
U
X
HSPKR+
HSPKR–
SPKR+
SPKR–
-6 dB
MIC+
MIC–
M+
M–
External to Device
75
75
Data Sheet
Handsfree
mic
Transmitter
microphone
Speakerphone
(40Ω nominal)
(32Ω min)
Speaker
Handset
Receiver
(150Ω)
Bias
), for
Bias
Ref