- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄373891 > AD6655 (Analog Devices, Inc.) IF Diversity Receiver PDF資料下載
參數(shù)資料
| 型號： | AD6655 |
| 廠商： | Analog Devices, Inc. |
| 英文描述： | IF Diversity Receiver |
| 中文描述： | IF分集接收機(jī) |
| 文件頁數(shù)： | 45/84頁 |
| 文件大?。?/td> | 2012K |
| 代理商： | AD6655 |
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頁當(dāng)前第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頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁
AD6655
In addition, the first input sample signal power is updated in
the accumulator, and the accumulation continues with the
subsequent input samples. Figure 77 illustrates the rms
magnitude monitoring logic.
Rev. 0 | Page 45 of 84
POWER MONITOR
HOLDING
REGISTER
ACCUMULATOR
FROM
MEMORY
MAP
FROM
INPUT
PORTS
LOAD
CLEAR
LOAD
IS COUNT = 1
DOWN
COUNTER
POWER MONITOR
PERIOD REGISTER
TO
MEMORY
MAP
TO
INTERRUPT
CONTROLLER
0
Figure 77. ADC Input RMS Magnitude Monitoring Block Diagram
For rms magnitude mode, the value in the signal monitor result
(SMR) register is a 20-bit fixed-point number. The following
equation can be used to determine the rms magnitude in dBFS
from the MAG value in the register. Note that if the signal
monitor period (SMP) is a power of 2, the second term in the
equation becomes 0.
RMS Magnitude
= 20 log
[
]
)
(
log
20
2
2
log
10
2
SMP
ceil
SMP
MAG
For ms magnitude mode, the value in the SMR is a 20-bit fixed-
point number. The following equation can be used to determine
the ms magnitude in dBFS from the MAG value in the register.
Note that if the SMP is a power of 2, the second term in the
equation becomes 0.
MS Magnitude
= 10 log
[
]
)
(
log
20
2
2
log
10
2
SMP
ceil
SMP
MAG
THRESHOLD CROSSING MODE
In the threshold crossing mode of operation, the magnitude of
the input port signal is monitored over a programmable time
period (given by SMPR) to count the number of times it crosses
a certain programmable threshold value. This mode is set by
programming Logic 1x (where x is a don’t care bit) in the signal
monitor mode bits of the signal monitor control register or by
setting the threshold crossing output enable bit in the signal
monitor SPORT control register. Before activating this mode,
the user needs to program the 24-bit SMPR and the 13-bit
upper threshold register for each individual input port. The
same upper threshold register is used for both signal
monitoring and gain control (see the ADC Overrange and Gain
Control section).
After entering this mode, the value in the SMPR is loaded into a
monitor period timer, and the countdown is started. The
magnitude of the input signal is compared with the upper
threshold register (programmed previously) on each input clock
cycle. If the input signal has a magnitude greater than the upper
threshold register, the internal count register is incremented by 1.
The initial value of the internal count register is set to 0. This
comparison and incrementing of the internal count register
continues until the monitor period timer reaches a count of 1.
When the monitor period timer reaches a count of 1, the value
in the internal count register is transferred to the signal monitor
holding register, which can be read through the SPI port or
output through the SPORT serial port.
The monitor period timer is reloaded with the value in the
SMPR register, and the countdown is restarted. The internal
count register is also cleared to a value of 0. Figure 78 illustrates
the threshold crossing logic. The value in the SMR register is
the number of samples that have a magnitude greater than the
threshold register.
POWER MONITOR
HOLDING
COA>B
TREGISTER
COA>B
MAP
FROM
MMAP
FROM
PORTS
LOAD
CLEAR
LOAD
IS COUNT = 1
CDOWN
POWER MONITOR
B
A
METO
MAP
INTTO
0
Figure 78. ADC Input Threshold Crossing Block Diagram
ADDITIONAL CONTROL BITS
For additional flexibility in the signal monitoring process, two
control bits are provided in the signal monitor control register.
They are the signal monitor enable bit and the complex power
calculation mode enable bit.
Signal Monitor Enable Bit
The signal monitor enable bit, located in Bit 0 of Register 0x112,
enables operation of the signal monitor block. If the signal
monitor function is not needed in a particular application, this
bit should be cleared to conserve power.
Complex Power Calculation Mode Enable Bit
When this bit is set, the part assumes that Channel A is digitizing
the I data and Channel B is digitizing the Q data for a complex
input signal (or vice versa). In this mode, the power reported is
equal to
2
2
Q
I
+
This result is presented in the Signal Monitor DC Value Channel A
register if the signal monitor mode bits are set to 00. The Signal
Monitor DC Value Channel B register continues to compute the
Channel B value.
DC CORRECTION
Because the dc offset of the ADC may be significantly larger
than the signal being measured, a dc correction circuit is included
to null the dc offset before measuring the power. The dc correction
circuit can also be switched into the main signal path, but this
may not be appropriate if the ADC is digitizing a time-varying
signal with significant dc content, such as GSM.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AD6655-125EBZ1 | IF Diversity Receiver |
| AD6655-150EBZ1 | IF Diversity Receiver |
| AD6655BCPZ-1051 | IF Diversity Receiver |
| AD6655BCPZ-1501 | IF Diversity Receiver |
| AD6655BCPZ-801 | IF Diversity Receiver |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD6655-125EBZ | 功能描述:BOARD EVAL W/AD6655 & SOFTWARE RoHS:是 類別:RF/IF 和 RFID >> RF 評估和開發(fā)套件，板 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 類型:GPS 接收器 頻率:1575MHz 適用于相關(guān)產(chǎn)品:- 已供物品:模塊 其它名稱:SER3796 |
| AD6655-125EBZ1 | 制造商:AD 制造商全稱:Analog Devices 功能描述:IF Diversity Receiver |
| AD6655-150EBZ | 功能描述:BOARD EVAL FOR 150MSPS AD6655 RoHS:是 類別:RF/IF 和 RFID >> RF 評估和開發(fā)套件，板 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 類型:GPS 接收器 頻率:1575MHz 適用于相關(guān)產(chǎn)品:- 已供物品:模塊 其它名稱:SER3796 |
| AD6655-150EBZ1 | 制造商:AD 制造商全稱:Analog Devices 功能描述:IF Diversity Receiver |
| AD6655ABCPZ-105 | 功能描述:IC IF RCVR 14BIT 105MSPS 64LFCSP RoHS:是 類別:RF/IF 和 RFID >> RF 其它 IC 和模塊 系列:- 標(biāo)準(zhǔn)包裝:100 系列:* |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。