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MC145483ENR2 Datasheet, PDF (1/24 Pages) Freescale Semiconductor, Inc – 3 V 13-BIT LINEAR PCM CODEC-FILTER | |||
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MOTOROLA
Freescale Semiconductor, Inc.
SEMICONDUCTOR TECHNICAL DATA
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by MC145483/D
3 V 13-Bit Linear PCM
Codec-Filter
The MC145483 is a 13âbit linear PCM CodecâFilter with 2s complement data
format, and is offered in 20âpin SOG, SSOP, and TSSOP packages, and a
32âpin QFN package. This device performs the voice digitization and
reconstruction as well as the band limiting and smoothing required for the voice
coding in digital communication systems. This device is designed to operate in
both synchronous and asynchronous applications and contains an onâchip
precision reference voltage.
This device has an input operational amplifier whose output is the input to the
encoder section. The encoder section immediately lowâpass filters the analog
signal with an active RâC filter to eliminate very high frequency noise from being
modulated down to the passband by the switched capacitor filter. From the
active RâC filter, the analog signal is converted to a differential signal. From this
point, all analog signal processing is done differentially. This allows processing
of an analog signal that is twice the amplitude allowed by a singleâended
design, which reduces the significance of noise to both the inverted and
nonâinverted signal paths. Another advantage of this differential design is that
noise injected via the power supplies is a commonâmode signal that is
cancelled when the inverted and nonâinverted signals are recombined. This
dramatically improves the power supply rejection ratio.
After the differential converter, a differential switched capacitor filter bandâ
passes the analog signal from 200 Hz to 3400 Hz before the signal is digitized
by the differential 13âbit linear A/D converter. The digital output is 2s
complement format.
The decoder digital input accepts 2s complement data and reconstructs it
using a differential 13âbit linear D/A converter. The output of the D/A is
lowâpass filtered at 3400 Hz and sinX/X compensated by a differential switched
capacitor filter. The signal is then filtered by an active RâC filter to eliminate the
outâofâband energy of the switched capacitor filter.
The MC145483 PCM CodecâFilter has a highâimpedance VAG reference pin
which allows for decoupling of the internal circuitry that generates the
midâsupply VAG reference voltage to the VSS power supply ground. This
reduces clock noise on the analog circuitry when external analog signals are
referenced to the power supply ground.
The MC145483 13âbit linear PCM CodecâFilter accepts both Short Frame
Sync and Long Frame Sync clock formats, and utilizes CMOS due to its reliable
lowâpower performance and proven capability for complex analog/digital VLSI
functions.
⢠Single 3 V Power Supply
⢠13âBit Linear ADC/DAC Conversions with 2s Complement Data Format
⢠Typical Power Dissipation of 8 mW, PowerâDown of 0.01 mW
⢠FullyâDifferential Analog Circuit Design for Lowest Noise
⢠Transmit BandâPass and Receive LowâPass Filters OnâChip
⢠Transmit HighâPass Filter May be Bypassed by Pin Selection
⢠Active RâC PreâFiltering and PostâFiltering
⢠OnâChip Precision Reference Voltage of 0.886 V for a â 5 dBm TLP
@ 600 â¦
⢠3âTerminal Input Op Amp Can be Used, or a 2âChannel Input Multiplexer
⢠Receive Gain Control from 0 dB to â 21 dB in 3 dB Steps in Synchronous
Operation
⢠PushâPull 300â⦠Power Drivers with External Gain Adjust
MC145483
20
1
DW SUFFIX
SOG PACKAGE
CASE 751D
20
1
20
1
1 32
SD SUFFIX
SSOP
CASE 940C
DT SUFFIX
TSSOP
CASE 948E
FC SUFFIX
QFN
CASE 1311
ORDERING INFORMATION
MC145483DW
MC145483SD
MC145483DT
MC145483FC
SOG Package
SSOP
TSSOP
QFN
REV 3
4/2003
For More Information On This Product,
Go to: www.freescale.com
MC145483
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