参数资料
| 型号： | AD9276BSVZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 19/48页 |
| 文件大小： | 0K |
| 描述： | IC ADC 12BIT LNA/VGA/AAF 100TQFP |
| 标准包装： | 1 |
| 类型： | AAF，ADC，解调器，LNA，VGA |
| 分辨率（位）： | 12 b |
| 采样率（每秒）： | 10M ~ 80M |
| 数据接口： | 串行，SPI? |
| 电压电源： | 模拟和数字 |
| 电源电压： | 1.8V，3V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 100-TQFP 裸露焊盘 |
| 供应商设备封装： | 100-TQFP-EP（14x14） |
| 包装： | 托盘 |
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AD9276
Rev. 0 | Page 26 of 48
I/Q Demodulator and Phase Shifter
The I/Q demodulators consist of double-balanced passive mixers.
The RF input signals are converted into currents by transconduc-
tance stages that have a maximum differential input signal
capability matching the LNA output full scale. These currents
are then presented to the mixers, which convert them to base-
band (RF LO) and twice RF (RF + LO). The signals are phase
shifted according to the codes programmed into the SPI latch
(see Table 8). The phase shift function is an integral part of the
overall circuit. The phase shift listed in Column 1 of Table 8 is
defined as being between the baseband I or Q channel outputs.
As an example, for a common signal applied to a pair of RF inputs
to an AD9276, the baseband outputs are in phase for matching
phase codes. However, if the phase code for Channel 1 is 0000
and that of Channel 2 is 0001, then Channel 2 leads Channel 1
by 22.5°.
Table 8. Phase Select Code for Channel-to-Channel Phase Shift
Φ Shift
I/Q Demodulator Phase
(SPI Register 0x2D[3:0])
0°
0000
22.5°
0001
45°
0010
67.5°
0011
90°
0100
112.5°
0101
135°
0110
157.5°
0111
180°
1000
202.5°
1001
225°
1010
247.5°
1011
270°
1100
292.5°
1101
315°
1110
337.5°
1111
Dynamic Range and Noise
Figure 53 is an interconnection block diagram of all eight
channels of the AD9276. More channels are easily added to the
summation (up to 32 when using an AD8021 as the summation
amplifier) by wire-OR connecting the outputs as shown. In
beamforming applications, the I and Q outputs of a number
of receiver channels are summed. The dynamic range of the
system increases by the factor 10 log10(N), where N is the
number of channels (assuming random uncorrelated noise).
The noise in the 8-channel example of Figure 53 is increased
by 9 dB, whereas the signal quadruples (18 dB), yielding an
aggregate SNR improvement of (18 9) = 9 dB.
The output-referred noise of the CW signal path depends on the
LNA gain, the selection of the external summing amplifier, and
the value of RFILT. To determine the output-referred noise, it is
important to know the active low-pass filter (LPF) values, RFILT
channel are 2 kΩ for RFILT and 0.8 nF for CFILT; these values
implement a 100 kHz single-pole LPF. In the case where eight
channels are summed, RFILT and CFILT are 250 Ω and 6.4 nF.
If the RF and LO are offset by 10 kHz, the demodulated signal is
10 kHz and is passed by the LPF. The single-channel mixing gain
from the RF input to the AD8021 output (for example, I1, Q1)
is approximately the LNA gain for RFILT and CFILT of 2 kΩ and
0.8 nF.
This gain can be increased by increasing the filter resistor while
maintaining the corner frequency. The factor limiting the
magnitude of the gain is the output swing and drive capability
of the op amp selected for the I-to-V converter, in this example,
the AD8021. Because any amplifier has limited drive capability,
there is a finite number of channels that can be summed. The
channel-summing limit relates directly to the current drive
capability of the amplifier used to implement the active low-
pass filter and current-to-voltage converter. The maximum
sum, when the AD8021 is used, is 32 channels of the AD9276;
that is, four AD9276s (4 × 8 = 32 channels) can be summed in
one AD8021.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AD9276XBCZ | 功能描述:IC ADC 12BIT LNA/VGA/AAF 制造商:analog devices inc. 系列:* 零件状态:上次购买时间 标准包装:1 |
| AD9276XSVZ | 功能描述:IC ADC 12BIT LNA/VGA/AAF 制造商:analog devices inc. 系列:* 零件状态:上次购买时间 标准包装:1 |
| AD9277 | 制造商:AD 制造商全称:Analog Devices 功能描述:Octal LNA/VGA/AAF/14-Bit ADC and CW I/Q Demodulator |
| AD9277-50EBZ | 功能描述:BOARD EVAL FOR AD9277 RoHS:是 类别:编程器，开发系统 >> 评估板 - 模数转换器 (ADC) 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- ADC 的数量:1 位数:12 采样率（每秒）:94.4k 数据接口:USB 输入范围:±VREF/2 在以下条件下的电源（标准）:- 工作温度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板，软件 |
| AD9277BSVZ | 功能描述:IC ADC 14BIT LNA/VGA/AAF 100TQFP RoHS:是 类别:集成电路 (IC) >> 数据采集 - ADCs/DAC - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:数据采集系统（DAS） 分辨率（位）:16 b 采样率（每秒）:21.94k 数据接口:MICROWIRE?，QSPI?，串行，SPI? 电压电源:模拟和数字 电源电压:1.8 V ~ 3.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP（6x6） 包装:托盘 |
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