- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383075 > HSP50214AVI (HARRIS SEMICONDUCTOR) Programmable Downconverter PDF資料下載
參數(shù)資料
| 型號： | HSP50214AVI |
| 廠商： | HARRIS SEMICONDUCTOR |
| 元件分類： | 通信及網(wǎng)絡 |
| 英文描述： | Programmable Downconverter |
| 中文描述： | SPECIALTY TELECOM CIRCUIT, PQFP120 |
| 文件頁數(shù)： | 19/60頁 |
| 文件大?。?/td> | 467K |
| 代理商： | HSP50214AVI |
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頁當前第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
19
Automatic Gain Control (AGC)
The AGC Section provides gain to small signals, after the
large signals and out-of-band noise have been filtered out, to
ensure that small signals have sufficient bit resolution in the
Resampling/Interpolating Halfband filters and the Output
Formatter. The AGC can also be used to manually set the
gain. The AGC optimizes the bit resolution for a variety of
input amplitude signal levels. The AGC loop automatically
adds gain to bring small signals from the lower bits of the 26-
bit programmable FIR filter output into the 16-bit range of the
output section. Without gain control, a signal at -72dBf
S
=
20log
10
(2
-12
) at the input would have only 4 bits of resolu-
tion at the output (12 bits less than the full scale 16 bits). The
potential increase in the bit resolution due to processing gain
of the filters can be lost without the use of the AGC.
Figure 23 shows the Block Diagram for the AGC Section.
The FIR filter data output is routed to the Resampling and
Halfband filters after passing through the AGC multipliers
and Shift Registers. The outputs of the Interpolating Half-
band filters are routed to the Cartesian to Polar coordinate
converter. The magnitude output of the coordinate converter
is routed through the AGC error detector, the AGC error
scaler and into the AGC loop filter. This filtered error term is
used to drive the AGC multiplier and shifters, completing the
AGC control loop.
The AGC Multiplier/Shifter portion of the AGC is identified in
Figure 23. The gain control from the AGC loop filter is sam-
pled when new data enters the Multiplier/Shifter. The limit
detector detects overflow in the shifter or the multiplier and
saturates the output of I and Q data paths independently.
The shifter has a gain from 0 to 90.31dB in 6.021dB steps,
where 90.31dB = 20log
10
(2
N
), when N = 15. The mantissa
provides an additional 6dB of gain in 0.0338dB steps where
6.0204dB = 20log
10
[1+(X)2
-15
], where X = 2
15
-1. Thus, the
AGC multiplier/shifter transfer function is expressed as:
where N, the shifter exponent, has a range of 0>N>15 and
X, the mantissa, has a range of 0>X>(2
15
-1).
Equation 14 can be expressed in dB,
The full AGC range of the Multiplier/Shifter is from 0 to
96.331dB (20log
10
[1+(2
15
-1)2
-15
] + 20log
10
[2
15
] = 96.331).
Figure 21 illustrates the transfer function of the AGC multi-
plier versus mantissa control for N = 0. Figure 22 illustrates
the complete AGC Multiplier/Shifter Transfer function for all
values of exponent and mantissa control.
The resolution of the mantissa was increased to 16 bits in
the A Version, to provide a theoretical AM modulation level of
-96dBc (depending on loop gain, settling mode and SNR).
This effectively eliminates AM spurious caused by the AGC
resolution.
For fixed gain, either set the upper and lower AGC limits to
the same value, or set the limits to minimum and maximum
gains and set the AGC gain to zero.
EVEN SYMMETRIC
EVEN TAP FILTER
ODD SYMMETRIC
EVEN TAP FILTER
EVEN SYMMETRIC
ODD TAP FILTER
ODD SYMMETRIC
ODD TAP FILTER
C0
CN-1
C
C
C0
CN-1
C0
CN-1
COEFFICIENT
NUMBER
COEFFICIENT
NUMBER
COEFFICIENT
NUMBER
COEFFICIENT
NUMBER
C
C
ASYMMETRIC
ODD TAP FILTER
C0
CN-1
COEFFICIENT
NUMBER
C
ASYMMETRIC
EVEN TAP FILTER
C0
CN-1
COEFFICIENT
NUMBER
C
COMPLEX FILTERS
C
Q(0)
C
I(N-1)
COEFFICIENT
NUMBER
I
REAL COEFFICIENT VALUE
C
C
Q(N-1)
REAL FILTERS
Definitions:
Even Symmetric: h(n) = h(N-n-1) for n = 0 to N-1
Odd Symmetric: h(n) = -h(N-n-1) for n = 0 to N-1
Asymmetric:
A filter with no coefficient symmetry.
Even Tap filter:
A filter where N is an even number.
Odd Tap filter:
A filter where N is an odd number.
Real Filter:
A filter implemented with real coefficients.
Complex Filters: A filter with quadrature coefficients.
FIGURE 20. DEMONSTRATION OF DIFFERENT TYPES OF
DIGITAL FIR FILTERS CONFIGURED IN THE
PROGRAMMABLE DOWNCONVERTER
C
V
C
Q
C
I
C0
CN
(EQ. 14)
AGC Mult/Shift Gain
2
N
1
X
( )
2
15
–
]
,
+
[
=
(EQ. 14A)
(AGC Mult/Shift Gain)dB
20log
10
2
N
1
X
( )
2
-15
]
+
[
(
)
=
HSP50214A
相關PDF資料 |
PDF描述 |
|---|---|
| HSP50214B | Programmable Downconverter |
| HSP50214BVC | Programmable Downconverter |
| HSP50214BVI | Programmable Downconverter |
| HT84 | ADSL Coupling Transformers |
| HT84-00594 | ADSL Coupling Transformers |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| HSP50214B | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Programmable Downconverter |
| HSP50214B_07 | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Programmable Downconverter |
| HSP50214BVC | 功能描述:上下轉(zhuǎn)換器 120L MQFP COMTEMP 14-BIT PROGRAMMABLE DOWNCONVERTER 65MSPS RoHS:否 制造商:Texas Instruments 產(chǎn)品:Down Converters 射頻:52 MHz to 78 MHz 中頻:300 MHz LO頻率: 功率增益: P1dB: 工作電源電壓:1.8 V, 3.3 V 工作電源電流:120 mA 最大功率耗散:1 W 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:PQFP-128 |
| HSP50214BVCZ | 功能描述:上下轉(zhuǎn)換器 120L MQFP COMTEMP 14-BIT PROG DWNCNVRT RoHS:否 制造商:Texas Instruments 產(chǎn)品:Down Converters 射頻:52 MHz to 78 MHz 中頻:300 MHz LO頻率: 功率增益: P1dB: 工作電源電壓:1.8 V, 3.3 V 工作電源電流:120 mA 最大功率耗散:1 W 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:PQFP-128 |
| HSP50214BVI | 功能描述:上下轉(zhuǎn)換器 120L MQFP INDTEMP 14-BIT PROGRAMMABLE DOWNCONVERTER 65MSPS RoHS:否 制造商:Texas Instruments 產(chǎn)品:Down Converters 射頻:52 MHz to 78 MHz 中頻:300 MHz LO頻率: 功率增益: P1dB: 工作電源電壓:1.8 V, 3.3 V 工作電源電流:120 mA 最大功率耗散:1 W 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:PQFP-128 |
發(fā)布緊急采購，3分鐘左右您將得到回復。