参数资料
型号: MC145483DT
厂商: Freescale Semiconductor
文件页数: 18/24页
文件大小: 0K
描述: IC PCM COD-FILT 3V 13BIT 20TSSOP
标准包装: 75
类型: PCM 编解码器/滤波器
数据接口: PCM 音频接口
分辨率(位): 13 b
ADC / DAC 数量: 1 / 1
三角积分调变:
电压 - 电源,数字: 2.7 V ~ 5.25 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 20-TSSOP(0.173",4.40mm 宽)
供应商设备封装: 20-TSSOP
包装: 管件
MC145483
FREQ
RO –
PI
PO –
PO +
VDD
VSS
VAG
TG
TI –
TI +
+
– 1
1
+
SHARED
DAC
0.886 V
REF
ADC
TRANSMIT
SHIFT
REGISTER
SEQUENCE
AND
CONTROL
DR
FSR
BCLKR
PDI
MCLK
BCLKT
FST
DT
RECEIVE
SHIFT
REGISTER
HB
VAG Ref
VDD
VSS
R*
Figure 1. MC145483 13–Bit Linear PCM Codec–Filter Block Diagram
DEVICE DESCRIPTION
A PCM Codec–Filter is used for digitizing and reconstruct-
ing the human voice. These devices are used primarily for
the telephone network to facilitate voice switching and trans-
mission. Once the voice is digitized, it may be switched by
digital switching methods or transmitted long distance (T1,
microwave, satellites, etc.) without degradation. The name
codec is an acronym from ‘‘COder’’ for the analog–to–digital
converter (ADC) used to digitize voice, and ‘‘DECoder’’ for
the digital–to–analog converter (DAC) used for reconstruct-
ing voice. A codec is a single device that does both the ADC
and DAC conversions.
To digitize intelligible voice requires a signal–to–distortion
ratio of about 30 dB over a dynamic range of about 40 dB.
This may be accomplished with a linear 13–bit ADC and
DAC. The MC145483 satisfies these requirements and may
be used as the analog front–end for voice coders using DSP
technology to further compress the digital data stream.
In a sampling environment, Nyquist theory says that to
properly sample a continuous signal, it must be sampled at a
frequency higher than twice the signal’s highest frequency
component. Voice contains spectral energy above 3 kHz, but
its absence is not detrimental to intelligibility. To reduce the
digital data rate, which is proportional to the sampling rate, a
sample rate of 8 kHz was adopted, consistent with a band-
width of 3 kHz. This sampling requires a low–pass filter to
limit the high frequency energy above 3 kHz from distorting
the in–band signal. The telephone line is also subject to
50/60 Hz power line coupling, which must be attenuated
from the signal by a high–pass filter before the analog–to–
digital converter. The MC145483 includes a high–pass filter
for compatibility with existing telephone applications, but it
may be removed from the analog input signal path by the
high–pass bypass pin.
The digital–to–analog conversion process reconstructs a
staircase version of the desired in–band signal, which has
spectral images of the in–band signal modulated about the
sample frequency and its harmonics. These spectral images
are called aliasing components, which need to be attenuated
to obtain the desired signal. The low–pass filter used to at-
tenuate these aliasing components is typically called a re-
construction or smoothing filter.
The MC145483 PCM Codec–Filter has the codec, both
presampling and reconstruction filters, and a precision volt-
age reference on–chip.
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.
相关PDF资料
PDF描述
MC145481DT IC PCM CODEC-FILTER 3V 20-TSSOP
MPC5566MZP144 IC MCU 32BIT 3MB FLASH 416PBGA
MCIMX515CJM6C MULTIMEDIA PROC 529-LFBGA
SPC5566MVR144 MCU 3MB FLASH 144MHZ 416-PBGA
JBXFD1G06MCSDSR CONN PLUG 6POS STR CABLE CRIMP
相关代理商/技术参数
参数描述
MC145483DW 功能描述:IC CODEC-FILTER PCM 3V 20-SOIC RoHS:否 类别:集成电路 (IC) >> 接口 - 编解码器 系列:- 标准包装:2,500 系列:- 类型:立体声音频 数据接口:串行 分辨率(位):18 b ADC / DAC 数量:2 / 2 三角积分调变:是 S/N 比,标准 ADC / DAC (db):81.5 / 88 动态范围,标准 ADC / DAC (db):82 / 87.5 电压 - 电源,模拟:2.6 V ~ 3.3 V 电压 - 电源,数字:1.7 V ~ 3.3 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-WFQFN 裸露焊盘 供应商设备封装:48-TQFN-EP(7x7) 包装:带卷 (TR)
MC145483DWR2 功能描述:IC CODEC-FILTER PCM 3V 20-SOIC RoHS:否 类别:集成电路 (IC) >> 接口 - 编解码器 系列:- 标准包装:2,500 系列:- 类型:立体声音频 数据接口:串行 分辨率(位):18 b ADC / DAC 数量:2 / 2 三角积分调变:是 S/N 比,标准 ADC / DAC (db):81.5 / 88 动态范围,标准 ADC / DAC (db):82 / 87.5 电压 - 电源,模拟:2.6 V ~ 3.3 V 电压 - 电源,数字:1.7 V ~ 3.3 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-WFQFN 裸露焊盘 供应商设备封装:48-TQFN-EP(7x7) 包装:带卷 (TR)
MC145483EG 功能描述:IC CODEC-FILTER PCM 3V 20-SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 编解码器 系列:- 标准包装:2,500 系列:- 类型:立体声音频 数据接口:串行 分辨率(位):18 b ADC / DAC 数量:2 / 2 三角积分调变:是 S/N 比,标准 ADC / DAC (db):81.5 / 88 动态范围,标准 ADC / DAC (db):82 / 87.5 电压 - 电源,模拟:2.6 V ~ 3.3 V 电压 - 电源,数字:1.7 V ~ 3.3 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-WFQFN 裸露焊盘 供应商设备封装:48-TQFN-EP(7x7) 包装:带卷 (TR)
MC145483EGR2 功能描述:IC CODEC-FILTER PCM 3V 20-SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 编解码器 系列:- 标准包装:2,500 系列:- 类型:立体声音频 数据接口:串行 分辨率(位):18 b ADC / DAC 数量:2 / 2 三角积分调变:是 S/N 比,标准 ADC / DAC (db):81.5 / 88 动态范围,标准 ADC / DAC (db):82 / 87.5 电压 - 电源,模拟:2.6 V ~ 3.3 V 电压 - 电源,数字:1.7 V ~ 3.3 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-WFQFN 裸露焊盘 供应商设备封装:48-TQFN-EP(7x7) 包装:带卷 (TR)
MC145483EJ 功能描述:IC CODEC-FI 13BIT 3V 20-TSSOP RoHS:是 类别:集成电路 (IC) >> 接口 - 编解码器 系列:- 标准包装:2,500 系列:- 类型:立体声音频 数据接口:串行 分辨率(位):18 b ADC / DAC 数量:2 / 2 三角积分调变:是 S/N 比,标准 ADC / DAC (db):81.5 / 88 动态范围,标准 ADC / DAC (db):82 / 87.5 电压 - 电源,模拟:2.6 V ~ 3.3 V 电压 - 电源,数字:1.7 V ~ 3.3 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-WFQFN 裸露焊盘 供应商设备封装:48-TQFN-EP(7x7) 包装:带卷 (TR)