ADI公司的AD9838" title="AD9838">AD9838是75MHz 的直接數字頻率合成器(DDS" title="DDS">DDS),工作電壓2.3V-5.5V,在2.3V時的功耗僅為11mW,輸出頻率高達8MHz,分辨率達0.02 Hz,正弦波和三角波輸出,3線SPI接口,主要用在頻率激勵/波形發生" title="波形發生">波形發生,頻率相位調整和調制,低功耗" title="低功耗">低功耗RF/通信系統,液體和氣體流量測量" title="流量測量">流量測量,傳感器應用以及測量與醫療設備.本文介紹了AD9838主要特性, 功能方框圖
EVAL-AD9838SDZ評估板主要特性,方框圖,電路圖以及材料清單和PCB元件布局.
AD9838:11 mW Power, 2.3 V to 5.5 V, 75 MHz Complete DDS
The AD9838 is a low power DDS device capable of producing high performance sine and triangular outputs. It also has an on-board comparator that allows a square wave to be produced for clock generation. Consuming only 11 mW of power at 2.3 V, the AD9838 is an ideal candidate for power-sensitive applications.
Capability for phase modulation and frequency modulation is provided. The frequency registers are 28 bits wide: with a 16 MHz clock rate, resolution of 0.06 Hz can be achieved; with a 5 MHz clock rate, the AD9838 can be tuned to 0.02 Hz resolution. Frequency and phase modulation are configured by loading registers through the serial interface and by toggling the registers using software or the FSELECT and PSELECT pins, respectively.
The AD9838 is written to via a 3-wire serial interface. This serial interface operates at clock rates up to 40 MHz and is compatible with DSP and microcontroller standards.
The device operates with a power supply from 2.3 V to 5.5 V. The analog and digital sections are independent and can be run from different power supplies; for example, AVDD can equal 5 V with DVDD equal to 3 V.
The AD9838 has a power-down pin (SLEEP) that allows external control of the power-down mode. Sections of the device that are not being used can be powered down to minimize current consumption. For example, the DAC can be powered down when a clock output is being generated.
The AD9838 is available in a 20-lead LFCSP_WQ package.
AD9838主要特性:
2.3 V to 5.5 V power supply
MCLK speed: 16 MHz (B grade), 5 MHz (A grade)
Output frequency up to 8 MHz
Sinusoidal and triangular outputs
On-board comparator
3-wire SPI interface
Extended temperature range: −40℃ to +125℃
Power-down option
11 mW power consumption at 2.3 V
20-lead LFCSP
AD9838應用:
Frequency stimulus/waveform generation
Frequency phase tuning and modulation
Low power RF/communications systems
Liquid and gas flow measurement
Sensory applications: proximity, motion, and defect detection
Test and medical equipment
圖1.AD9838功能方框圖
EVAL-AD9838SDZ評估板
The AD9838 is a 16 MHz low power DDS device capable of producing high performance sine and triangular outputs. It also has an on-board comparator that allows a square wave to be produced for clock generation. Consuming only 20 mW of power at 3 V makes the AD9838 an ideal candidate for power-sensitive applications.
The EVAL-AD9838SDZ board is used in conjunction with a EVAL-SDP-CB1Z SDP board available from Analog Devices, Inc. The USB-to-SPI communication to the AD9838 is completed using this Blackfin®based development board.
A high performance, on-board 16 MHz trimmed general oscillator is available to use as the master clock for the AD9838 system. Various links and SMB connectors are also available on the EVAL-AD9838SDZ board to maximize usability.
Complete specifications for the AD9838 are provided in the AD9838 data sheet, available from Analog Devices, and should be consulted in conjunction with this user guide when using the evaluation board.
EVAL-AD9838SDZ評估板主要特性:
Full featured evaluation board for the AD9838 evaluation board
Graphical user interface software for board control and data analysis
Connector to EVAL-SDP-CB1Z system demonstration platform (SDP) board
Various power supply and reference link options
EVAL-AD9838SDZ評估板應用:
Biomedical sensors
Bioelectrical impedance analysis
Electrochemical analysis
Impedance spectroscopy
Complex impedance measurement
Nondestructive testing
圖2.EVAL-AD9838SDZ評估板功能方框圖
圖3.EVAL-AD9838SDZ評估板電路圖(1)
圖4.EVAL-AD9838SDZ評估板電路圖(2)
圖5.EVAL-AD9838SDZ評估板元件布局圖
EVAL-AD9838SDZ評估板材料清單:
詳情請見:
http://www.analog.com/static/imported-files/data_sheets/AD9838.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-268.pdf
