- 您現在的位置：買賣IC網 > PDF目錄367816 > PCF50732H (NXP SEMICONDUCTORS) Baseband and audio interface for GSM PDF資料下載
參數資料
| 型號： | PCF50732H |
| 廠商： | NXP SEMICONDUCTORS |
| 元件分類： | 通信及網絡 |
| 英文描述： | Baseband and audio interface for GSM |
| 中文描述： | SPECIALTY TELECOM CIRCUIT, PQFP48 |
| 封裝： | PLASTIC, LQFP-48 |
| 文件頁數： | 10/64頁 |
| 文件大小： | 322K |
| 代理商： | PCF50732H |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁當前第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁
1999 May 03
10
Philips Semiconductors
Objective specification
Baseband and audio interface for GSM
PCF50732
9.1.1
GMSK
MODULATOR
The input signal of the GMSK modulator is a bitstream
coming from the baseband serial interface, with a
sampling frequency of 270.833 kHz. Typically 148 bits are
modulated during a normal burst, and 88 bits during an
access burst. Using this bitstream, the GMSK modulator
generates digital I and Q components as described in
“GSM recommendation 05.04”
This is done in three steps:
1.
First the incoming bitstream is differentially encoded
by an EXOR operation on the actual bit and the
previous bit
2.
The instantaneous phase (
) is calculated using a
gaussian filter with an impulse response of 4 taps
3.
A look-up table provides the cosine (I component) and
the sine values (Q component) of the phase (
).
The look-up table also interpolates the signal to a
16 times higher frequency (4.333 MHz).
9.1.2
10-
BIT
DAC
S
The two 10-bit DACs are working at a sampling rate of
4.3333 MHz. They convert the digital I and Q components
of the GMSK modulator to differential analog
I and Q signals.
9.1.3
L
OW
-
PASS FILTER
The analog output signals of the DACs are filtered by
analog reconstruction low-pass filters.
These filters remove high frequency components of the
DAC output signals and attenuate components around the
4.3333 MHz sampling frequency. The low-pass filters
have a cut-off frequency of approximately 300 kHz, with
very linear phase behaviour in the pass band.
9.2
Baseband receive path
The baseband receive path consists of two parts:
Receive ADC:
Σ
analog-to-digital converters
Decimation filter
: digital decimation filters for I and Q.
The baseband receive section can be switched between
two modes of operation:
ZIF (zero IF) mode for radio sections, which convert the
receive signal down to baseband. In this mode the ADC
is sampled at 6.5 MHz, the decimation filter samples
down by a factor of 24 with a pass band as specified in
Fig.3. The serial interface output BDIO delivers
2
×
12-bit values for I and Q components at
270.833 kHz.
NZIF (near zero IF) mode for radio sections, which
converts the receive signal down to a centre frequency
of 100 kHz. In this mode the ADC is sampled at 13 MHz,
the decimation filter samples down by a factor of 24 with
a pass band as specified in Fig.3. The serial interface
output BDIO delivers 2
×
12-bit values for I and Q
components at 541.667 kHz.
9.2.1
R
ECEIVE
ADC
The receive ADCs are
Σ
analog-to-digital converters that
convert differential input signals into1-bit data streams with
a sampling frequency of 6.5 or 13 MHz.
9.2.2
D
IGITAL DECIMATION FILTER
Digital filtering is required for:
Suppression of out-of-band noise produced by the
Σ
ADC
Decimation of the sampling rate (6.5 or 13 MHz) by 24
System level filtering.
The digital filtering is performed by a digital FIR filter with a
group delay for this running average filter of approximately
23 or 11.5
μ
s respectively. The filter uses twos
complement arithmetic.
相關PDF資料 |
PDF描述 |
|---|---|
| PCF7991AT | Advanced Basestation IC, ABIC |
| PCF80C31BH4-24H | CMOS single-chip 8-bit microcontrollers |
| PCB80C51BH-2H | CMOS single-chip 8-bit microcontrollers |
| PCB80C51BH-2P | CMOS single-chip 8-bit microcontrollers |
| PCB80C51BH-2WP | CMOS single-chip 8-bit microcontrollers |
相關代理商/技術參數 |
參數描述 |
|---|---|
| PCF5075 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Power Control/Management |
| PCF5075TDK-T | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Power Control/Management |
| PCF5077T | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Power amplifier controller for GSM and PCN systems |
| PCF5078 | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Power amplifier controller for GSM and PCN systems |
| PCF5078T | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Power amplifier controller for GSM and PCN systems |
發(fā)布緊急采購，3分鐘左右您將得到回復。