参数资料
型号: ISL5416
厂商: Intersil Corporation
英文描述: Four-Channel Wideband Programmable DownConverter
中文描述: 四通道可编程宽带下变频器
文件页数: 17/71页
文件大小: 2013K
代理商: ISL5416
17
the number of passes in the computation. A listing the
accuracy and gain is provided below.
With maximum gain and with full scale I and Q inputs equal
to ~+/-1.0, the maximum output from the computation is
1.414 * 1.647 = 2.329. The error detector subtracts the
magnitude from the programmable AGC Threshold value.
The AGC Threshold value is set in IWA register *009h and
should be programmed to K times the desired magnitude of
the I/Q where K is the gain of the magnitude computation.
Two adjustment/settling modes are provided in the ISL5416.
In the mean settling mode, the loop adjusts the gain so that
the average magnitude is equal to the programmed set point.
In this mode, the error is scaled by the loop gain and
integrated to compute the forward gain. The loop settles to
the final value asymptotically because the size of the
adjustment decreases as the error decreases. The initial
settling from large errors is fast, but the final pull in is slower.
After the loop has settled, the small adjustment size causes
minimal AM distortion of the signal. The other settling mode
is the median mode. In this mode, the sign of the error is
used increase or decrease the gain by a fixed amount. The
amount of the adjustment is programmed by the loop gain.
The loop settles to the point where there are an equal
number of samples above and below the set point. The loop
settling is roughly linear in dB, but after the loop has settled,
the step size remains the same, so the amount of AM
distortion may be objectionable. The ISL5416 provides two
programmable loop gains, each with a separate attack and
decay settling. The micro-processor can control the loop
gain, or the AGC counters can select the loop gain, so a
large loop gain can be used for initial settling and a smaller
one for tracking. The counters can also select the settling
mode, so the median mode can be used at the beginning of
each time slot and the mean mode used after the initial
settling.
The AGC loop filter is an accumulator (integrator). The
output of the accumulator is the forward gain word that
controls the barrel shifter and multiplier, closing the loop.
There are programmable limits on the accumulator range to
minimize settling time by restricting the AGC to only that
portion of the 96 dB range that is needed. The accumulator
can be loaded by the microprocessor. The gain load is
double buffered-the gain is first loaded into a holding register
by the uP. The gain is then transferred from the holding
register to the accumulator by a write to a special address
location or by the SYNCInX if enabled in IWA *000. The AGC
can be set to a fixed gain either by setting the both upper
and lower gain limits to the desired gain or by setting the
loop gain to zero and programming the accumulator directly.
The bit weighting for the AGC loop is provided in Table 86.
I
TABLE 5. AGC MAGNITUDE COMPUTATION ACCURACY AND
GAIN
PASSES
ERROR +/- (dB)
GAIN
2
0.48
1.581
3
0.13
1.630
4
0.03
1.642
8
0.0001
1.647
ISL5416 AGC Forward Gain Response
0
12
24
36
48
60
72
84
96
0
32768
65536
98304
131072
163840
196608
229376
262144
Code
d
FIGURE 5A. ISL5416 AGC FORWARD GAIN RESPONSE
ISL5416 AGC Forward Gain Response
Magnified View
0
1
2
3
4
5
6
0
2048
4096
6144
8192
10240
12288
14336
16384
Code
d
FIGURE 5B. ISL5416 AGC FORWARD GAIN RESPONSE
MAGNIFIED VIEW (ACTUAL AND IDEAL LINEAR
IN dB)
ISL5416
相关PDF资料
PDF描述
ISL5416EVAL Four-Channel Wideband Programmable DownConverter
ISL5416KI Four-Channel Wideband Programmable DownConverter
ISL54205A MP3/USB 2.0 High Speed Switch with Negative Signal Handling
ISL54205AIRUZ-T MP3/USB 2.0 High Speed Switch with Negative Signal Handling
ISL54205AIRZ MP3/USB 2.0 High Speed Switch with Negative Signal Handling
相关代理商/技术参数
参数描述
ISL5416_04 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Four-Channel Wideband Programmable DownConverter
ISL5416EVAL 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Four-Channel Wideband Programmable DownConverter
ISL5416EVAL1 功能描述:EVALUATION PLATFORM FOR ISL5416 RoHS:是 类别:RF/IF 和 RFID >> RF 评估和开发套件,板 系列:- 标准包装:1 系列:- 类型:GPS 接收器 频率:1575MHz 适用于相关产品:- 已供物品:模块 其它名称:SER3796
ISL5416KI 功能描述:上下转换器 QUAD WIDEBAND DOWN CONVERTER, 256 CABGA RoHS:否 制造商:Texas Instruments 产品:Down Converters 射频:52 MHz to 78 MHz 中频:300 MHz LO频率: 功率增益: P1dB: 工作电源电压:1.8 V, 3.3 V 工作电源电流:120 mA 最大功率耗散:1 W 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:PQFP-128
ISL5416KIZ 制造商:Intersil Corporation 功能描述:LEAD-FREE QUAD WIDEBAND DOWN CONVERTER, 256 CABGA - Trays 制造商:Intersil Corporation 功能描述:PB-FREE W/ANNEAL QUAD DIGITAL DOWNCONVER 制造商:Intersil 功能描述:QD WIDEB& DWN CNVRTR 256 CABGA