FMC277- FMC sub-card based on eight channel 256Ksps 24BIT AD bio-electric vibration detection

Item No.: 277
1.Overview of the board card
The board card is an EIGHT-channel low-speed FMC sub-card based on THE AD7768 AD chip design, which supports DC coupling. The product is applied to signal acquisition such as bio-electricity, brainwave, sound, vibration, etc.

2. Parameters and performance of board card
The function of the board card Parameters Contents
ADC Chip type AD7768
Channel amount Eight channel ADC
Sampling rate 256 kSPS
Data bits 24bit
Digital interface SPI
Analog interface Dc coupling
Analog input  differential input  ±1V
Input resistance 50Ω
Analog standard  
DAC no  
Connector type FMC-LPC ASP_134604_01
  Front panel MDR26
Standard FMC  ANSI/VITA 57.1 - 2008
Size 69X76.5mm
Weight within heat sink
Power supply +12V@1A
Power consumption 8W
Working temperature Industrial  -20℃ to +70℃
Support motherboard Xilinx board V6V7KUVU ZYNQZU development board
Orihard board 13627036728833027439


3.3 AD subcard application example

This design is mainly based on the FMC structure to complete the eight channel AD input. The analog signals detected by electrodes or other sensors should be filtered first, and then amplified by AD8232, so that the eight channel 24-bit AD7768 can easily obtain the output signal. The sub-card is connected to the PCI-E board card (Product no. 136) through the FMC standard connector of xilinx. It can be connected to PC or other devices with PCI-E interface and can be used in conjunction with the upper computer. It is mainly used for the application development of bio-electricity (brainwave) detection.

Brain waves are rhythmical, and we can determine the pattern of brain waves by means of collection, extraction and pattern recognition, so as to define this kind of brain waves to achieve some peripheral control. For example, delta wave is initiated in the brain, the electrodes pick up the rhythm signal, which is defined as the alarm signal and triggers the buzzer alarm.
The rhythmic main components of brainwaves are divided according to their frequencies, including the following waves:
(1)δ wave (0.5~4Hz) with amplitude of 20~200μV, also known as sleep wave, which can be observed only during sleep when healthy people are awake and almost free from δ waves. δ waves occur in the third and fourth stages of sleep. δ waves may also occur during deep anesthesia and brain lesions.
(2) θ waves (4 to 8Hz), in the range of 20 to 150 μV, occur during sleepiness and are a sign that the central nervous system is inhibited, meaning that θ waves can be observed when a person is tired. The parietal lobe and occipital lobe are more obvious in general.
(3) α wave (8~12Hz), which is the basic wave to determine the speed of eeg, is the basic rhythm in normal adult human brain. Alpha waves can be detected in the occipital region of the skull with an amplitude of 20 to 100 V. Alpha waves are the most prominent rhythmical brain waves and can be generated throughout the cortex. Alpha waves appear when awake, quiet and closed, with amplitude varying regularly from small to large and then from large to small, showing an angular pattern.
(4) β wave (14~30Hz) with amplitude of 5~22 V. This rhythm is usually observed in the occipital and frontal lobes of the brain, and beta waves occur when we are thinking with our eyes closed or when the cerebral cortex is tense and excited.
This product can clearly and efficiently detect the rhythmic electrical signals of bioelectricity (brainwave), and connect to PC or other devices through PCI-E. It has good expansion ability and can realize brainwave control with upper computer software.