ADIAD5700HART调制解调器评估方案
2012-03-09
作者:ADI公司
ADI公司的AD5700/AD5700-1是HART FSK半双工调制解调器单片解决方案,和HART物理层的需求兼容,集成了所有需要的滤波,信号调理,调制和解调,信号产生功能,外接元件很少,2V-5.5V电源,接口电平1.71V-5.5V,主要用在场发送器,HART复接器,HART网络连接,PLC和DCS模拟I/O模块。本文介绍了AD5700主要特性,方框图,连接图,回路供电的发送器框图,HART智能发送器参考电路图以及AD5700/AD5700-1 HART调制解调器评估板主要特性,电路图,材料清单和PCB元件布局图。
The AD5700/AD5700-1 are single-chip solutions, designed and specified to operate as a HART® FSK half-duplex modem, complying with the HART physical layer requirements. The AD5700/AD5700-1 integrate all of the necessary filtering, signal detection, modulating, demodulating and signal generation functions, thus requiring few external components. The 0.5% precision internal oscillator on the AD5700-1 greatly reduces the board space requirements, making it ideal for line-powered applications in both master and slave configurations. The maxi- mum supply current consumption is 115 μA, making the AD5700/ AD5700-1 an optimal choice for low power loop-powered applications. Transmit waveforms are phase continuous 1200 Hz and 2200 Hz sinusoids. The AD5700/AD5700-1 contain accurate carrier detect circuitry and use a standard UART interface.
AD5700主要特性:
HART-compliant fully integrated FSK modem
1200 Hz and 2200 Hz sinusoidal shift frequencies
115 μA maximum supply current in receive mode
Suitable for intrinsically safe applications
Integrated receive band-pass filter
Minimal external components required
Clocking optimized for various system configurations
Ultralow power crystal oscillator (60 μA maximum)
External CMOS clock source
Precision internal oscillator (AD5700-1 only)
Buffered HART output—extra drive capability
8 kV HBM ESD rating
2 V to 5.5 V power supply
1.71 V to 5.5 V interface
−40℃ to +125℃ operation
4 mm × 4 mm LFCSP package
HART physical layer compliant UART interface
AD5700应用:
Field transmitters
HART multiplexers
PLC and DCS analog I/O modules
HART network connectivity
图1。AD5700方框图
图2。AD5700/01外接和内部滤波器选择的连接图
图3。AD5700回路供电的发送器框图
图4。AD5700 HART智能发送器参考电路图
AD5700/AD5700-1 HART调制解调器评估板
This user guide describes the evaluation board for the AD5700/ AD5700-1 Highway Addressable Remote Transducer (HART®) modem. This board can be used to evaluate either the AD5700 or the AD5700-1 part. Both can operate from a single 2 V to 5.5 V supply, with the AD5700-1 having the added feature of an integrated oscillator. Complete specifications for both products can be found in the AD5700/AD5700-1 data sheet available from Analog Devices, Inc., which should be consulted in conjunction with this user guide when using the evaluation board.
HART调制解调器评估板主要特性:
Convenient connections for power through screw
Terminal block
Use of on-chip RC oscillator or an external crystal
Various link options
EQUIPMENT NEEDED
Host controller with UART interface
图5。HART调制解调器评估板外形图
图6。HART调制解调器评估板电路图
HART调制解调器评估板材料清单(BOM):
图7。HART调制解调器评估板元件布局图
详情请见:
http://www.analog.com/static/imported-files/data_sheets/AD5700_5700-1.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-382.pdf