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| AD9680雙路14位1GSPS模數轉換方案 |
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| 文章來源： 更新時間：2014/12/19 10:16:00 |
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ADI公司的AD9680是雙路14位1GSPS模數轉換器(ADC),IF取樣頻率高達2GHz, JESD204B (Subclass 1)碼串行數字輸出,1GSPS時每路總功耗1.65W,340MHz時的SFDR=dBFS,1GHz時為80dBFS,1GSPS時的噪音密度=-154dBFS/Hz, DNL = ±0.5 LSB INL = ±2.5 LSB, 1.25 V, 2.5 V和3.3 V工作電壓,主要用在通信,多頻帶多模式數字接收器如3G/4G, TD-SCDMA, W-CDMA, GSM, LTE,通用軟件無線電,超寬帶衛(wèi)星接收器,儀表,雷達,HFC數字反向通路接收器等.本文介紹了AD9680產品亮點和主要特性,框圖, 評估板AD9680-1000EBZ主要特性,測試連接圖,電路圖,材料清單和PCB設計文件.
The AD9680 is a dual, 14-bit, 1 GSPS analog-to-digital converter (ADC). The device has an on-chip buffer and sample-and-hold circuit designed for low power, small size, and ease of use. This device is designed for sampling wide bandwidth analog signals of up to 2 GHz. The AD9680 is optimized for wide input bandwidth, high sampling rate, excellent linearity, and low power in a small package.
The dual ADC cores feature a multistage, differential pipelined architecture with integrated output error correction logic. Each ADC features wide bandwidth inputs supporting a variety of user-selectable input ranges. An integrated voltage reference eases design considerations.
The analog input and clock signals are differential inputs. Each ADC data output is internally connected to two digital downconverters (DDCs). Each DDC consists of four cascaded signal processing stages: a 12-bit frequency translator (NCO), and four half-band decimation filters.
In addition to the DDC blocks, the AD9680 has several functions that simplify the automatic gain control (AGC) function in the communications receiver. The programmable threshold detector allows monitoring of the incoming signal power using the fast detect output bits of the ADC. If the input signal level exceeds the programmable threshold, the fast detect indicator goes high. Because this threshold indicator has low latency, the user can quickly turn down the system gain to avoid an overrange condition at the ADC input.
Users can configure the Subclass 1 JESD204B-based high speed serialized output in a variety of one-, two-, or four-lane configurations, depending on the DDC configuration and the acceptable lane rate of the receiving logic device. Multiple device synchronization is supported through the SYSREF± and SYNCINB± input pins.
The AD9680 has flexible power-down options that allow significant power savings when desired. All of these features can be programmed using a 1.8 V to 3.3 V capable 3-wire SPI.
The AD9680 is available in a Pb-free, 64-lead LFCSP and is specified over the −40℃ to +85℃ industrial temperature range. This product is protected by a U.S. patent.
AD9680產品亮點:
1. Wide full power bandwidth supports IF sampling of signals up to 2 GHz.
2. Buffered inputs with programmable input termination eases filter design and implementation.
3. Four integrated wideband decimation filters and numerically controlled oscillator (NCO) blocks supporting multiband receivers.
4. Flexible serial port interface (SPI) controls various product features and functions to meet specific system requirements.
5. Programmable fast overrange detection.
6. 9 mm × 9 mm 64-lead LFCSP
AD9680主要特性:
JESD204B (Subclass 1) coded serial digital outputs
1.65 W total power per channel at 1 GSPS (default settings)
SFDR = 85 dBFS at 340 MHz, 80 dBFS at 1 GHz
SNR = 65.3 dBFS at 340 MHz (AIN = −1.0 dBFS), 61.4 dBFS at 1 GHz
ENOB = 10.8 bits at 10 MHz
DNL = ±0.5 LSB INL = ±2.5 LSB
Noise density = −154 dBFS/Hz at 1 GSPS
1.25 V, 2.5 V, and 3.3 V dc supply operation
No missing codes
Internal ADC voltage reference
Flexible input range and termination impedance
1.46 V p-p to 1.94 V p-p (1.70 V p-p nominal)
400 Ω, 200 Ω, 100 Ω, and 50 Ω differential
2 GHz usable analog input full power bandwidth
95 dB channel isolation/crosstalk
Amplitude detect bits for efficient AGC implementation
2 integrated wideband digital processors per channel
12-bit NCO, up to 4 cascaded half-band filters
Differential clock input
Integer clock divide by −1, 2, 4, or 8
Flexible JESD204B lane configurations
Small signal dither
AD9680應用:
Communications
Diversity multiband, multimode digital receivers
3G/4G, TD-SCDMA, W-CDMA, GSM, LTE
General-purpose software radios
Ultrawideband satellite receivers
Instrumentation
Radars
Signals intelligence (SIGINT)
DOCSIS 3.0 CMTS upstream receive paths
HFC digital reverse path receivers
圖1. AD9680功能框圖
AD9680評估板AD9680-1000EBZ
This user guide describes the AD9680 evaluation board AD9680-1000EBZ which provides all of the support circuitry required to operate the ADC in its various modes and configurations. The application software used to interface with the devices is also described.
The AD9680-1000EBZ and AD9234-1000EBZ are evaluation boards for the AD9680-1000 14-Bit, 1000MSPS JESD204B, Dual Analog-to-Digital Converter and the AD9234-1000 12-Bit, 1000MSPS JESD204B, Dual Analog-to-Digital Converter respectively. The reference designs provide all of the support circuitry required to operate the ADC in its various modes and configurations. It is designed to interface directly with the ADS7-V1EBZ data capture card, allowing users to download captured data for analysis. The Visual Analog software package, which is used to interface with the device’s hardware, allows users to download captured data for analysis with a user-friendly graphical interface. The SPI Controller software package is also compatible with this hardware, and allows the user to access the SPI programmable features of the AD9680 and AD9234. The user guide wiki provides documentation and instructions to configure the device for performance evaluation in the lab.
AD9680評估板AD9680-1000EBZ主要特性:
Full featured evaluation board for the AD9680 and AD9234
SPI interface for setup and control
Wide band Balun driven input
No external supply needed. Uses 12V-1A and 3.3V-3A supplies from FMC
VisualAnalog® and SPI controller software interfaces
圖2. 評估板AD9680-1000EBZ外形圖
圖3. 評估板AD9680-1000EBZ測試連接圖
圖4. 評估板AD9680-1000EBZ電路圖(1)
圖5. 評估板AD9680-1000EBZ電路圖(2)
圖6. 評估板AD9680-1000EBZ電路圖(3)
圖7. 評估板AD9680-1000EBZ電路圖(4)
圖8. 評估板AD9680-1000EBZ電路圖(5)
圖9. 評估板AD9680-1000EBZ電路圖(6)
圖10. 評估板AD9680-1000EBZ電路圖(7)
圖11. 評估板AD9680-1000EBZ電路圖(8)
圖12. 評估板AD9680-1000EBZ電路圖(9)
圖13. 評估板AD9680-1000EBZ電路圖(10) |
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