ADI’s Medical Ultrasound Solutions
Medical Ultrasound System Theory and Typical Architecture
the transmit voltage is increased, but it is limited by safety requirements
from agencies such as the FDA.
By transmitting acoustic energy into the body and receiving and processing the
returning reflections, ultrasound systems can generate images of internal organs
and structures, map blood flow and tissue motion, and provide highly accurate
blood velocity information.
Ultrasound systems include transducers, high voltage multiplexing, high voltage
transmitters, Tx/Rx switches, receive-path Analog Front End (AFE), beamformers,
beamformed digital signal processing, display processing and peripherals. The AFE
includes a low-noise amplifier (LNA); a variable-gain amplifier (VGA); an
antialiasing filter (AAF); and an analog-to-digital converter (ADC). There are two
kinds of beam-formers— digital beamformers and analog beamformers for
different applications.
•
Beam-Former Complexity— High image quality requires a large number of
beam-forming channels. The increased complexity in turn leads to higher
power dissipation and requires more imaging volume to implement
•
Heat Dissipation— Heat dissipation is an important issue for miniaturized
devices, particularly when improving image quality is the goal.
Historically, the large number of high-performance transmitters and receivers
required to implement these imaging systems resulted in large and expensive
cart-based implementations. Recently, advances in integration have allowed
system engineers to design smaller, lower cost, and more portable imaging
solutions with performance equal to cart-based systems.
Medical Ultrasound System Design Considerations and Major
Challenges
Total solutions from ADI
•
AFE Circuit Performance, such as: noise performance, SNR (Signal to Noise
Ratio), and DR (Dynamic Range). Typical required DR is: 70dB for B mode,
140dB for PWD (Pulse Wave Doppler) and 160dB for CWD (Continuous Wave
Doppler).
•
Transmit Voltage— High transmit voltages are needed to improve signal
penetration and also for harmonic imaging. The acoustic power grows as
ADI provides an extensive selection of amplifiers, data conversion, signal
processing and power management solutions that maximize image quality, and
reduce power consumption and cost in cart-based and battery-powered portable
ultrasound equipment. In addition, ADI provides evaluation boards, gerber files,
simulation tools and applications expertise to support customer design and
development efforts.
Main Signal Chain :
HV
AMP
ADuM240x
AD9709/AD9763/65/67
Isolation
DAC
AD9271/72/73/76/77/78/79
Beamformer
Central Control
Processor
ADI Integrated Solution
LNA-VGA-ADC Array (Up to 256 Channels)
AD8332/34/35
HV Mux and
T/R Switches
T/R
Switches
LNA
VGA
ADC
AD8432
ADA4899
Switch Control
Transducer
Array
AD9212/22/28
AAF
ADA4939/AD8132
ADG714/
ADG619
Amp
●
●
●
●
●
●
Gain
Control
DAC
Clocks
AD5326
/53xx
ADV7180/ADV7441/AD9880
Video Decoder
/
HDMI receiver
AD951x/952x/ADCLK854
ADC
I/Q
Processing
Other Key Components
FPGA
Digital Rx
Beam former
Amp
AD8333/39
Digital Potentiometer
Interface
References
Signal Control
Supervisory
Thermal Management
ADC
AD7685/86
AD7980/82
ADA4898/ADA4841 as I-V
CW
Doppler
Processing
Image and
Motion
Processing
(B Mode)
Color
Doppler
Processing
(F Mode)
Video
Compression
ADSP-21462
Video DAC
/ Video
Encoder
ADV7125/ADV739x
ADA4841/ADA4004 as Filter
ADA4932/ADA4841 as ADC Driver
ADV202/212/216
Audio
DAC
ADAU1361/1761/SSM2604
Power Management Solution
www.analog.com
Amp/
Filter
ADA4420-3/ADA4417-3
Amp
DVR
Integrated AFE Solutions
ADI’s AD927x Integrated Analog Front End (AFE) series provide more options to address
ultrasound system design challenges. Customers can select an AFE to best match RX
requirements for performance, power consumption, and imaging mode.
Parameter
ADC resolution
Input Voltage(0.1dB compression)
LNA Gain
Unit
AD9272
AD9273
AD9276
AD9277
AD9279
bit
12
12
12
14
12
AD9278
12
mVp-p
733/550/367
733/550/367
733/550/367
733/550/367
1000/750/450
1000/750/450
dB
15.6/17.9/21.3
15.6/17.9/21.3
15.6/17.9/21.3
15.6/17.9/21.3
15.6/17.9/21.3
15.6/17.9/21.3
LNA Input Noise Voltage
nV/√Hz
0.98/0.86/0.75
1.6/1.42/1.26
0.98/0.86/0.75
0.98/0.86/0.75
0.95/0.85/0.75
1.6/1.42/1.27
TGC Input Noise Voltage @ Max VGA gain, Rs=0
nV/√Hz
1.26/1.04/0.85
1.94/1.64/1.38
1.26/1.04/0.85
1.26/1.04/0.85
1.12/0.96/0.81
1.7/1.5/1.3
Input Noise Current
pA/√Hz
1
1
1
1
2.5
1.5
Power TGC @40MHz
mW/ch
191
104
191
191
141
89
Power TGC @65MHz
mW/ch
209
111 @50MHz
209
209
150
92@50MHz
Power CW
mW/ch
119
72
85
85
60
25
TGC Output DR mid channel gain
dB
66.9
64.6
66.9
68.6
68.6
67.8
TGC Output SNR@ -1dBFS output
dB
65
64
65
67.5
67.4
65.4
VGA Gain Range
dB
42
42
42
42
45
45
MHz
8~18
8~18
8~18
8~18
8~18
8~18
AAF Low Pass Cutoff
Sampling Rate (Max)
CW Input DR
CW Input Noise Voltage
(including output amplifiers)
MSPS
80 (80/65/40)
50 (50/40/25)
80 (80/65/40)
80 (80/65/40)
80 (80/65/40)
50 (50/40/25)
dBFS/√Hz
161/161/160
160/159/158
164/162/160
164/162/160
164/162/160
162/160/157
nV/√Hz
2.35/1.82/1.31
2.6/2.1/1.6
1.5/1.4/1.3
1.5/1.4/1.3
1.5/1.4/1.3
2.0/1.9/1.8
CW LO Interface
CW Output
Package
4xLO
4xLO
4xLO
4xLO
4xLO
4xLO
Compatible with
AD8339
Compatible with
AD8339
Current
Current
Current
Current
14mmx14mm TQFP
14mmx14mm TQFP
10mmx10mm BGA
14mmx14mm TQFP
14mmx14mm TQFP
10mmx10mm BGA
10mmx10mm BGA
Supply Voltage
V
1.8/3.0
1.8/3.0
1.8/3.0
1.8/3.0
1.8/3.0
1.8/3.0
Operating Temperature
V
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
−40°C to +85°C
Other Related Products
Part
Description
AD8339
DC to 50 MHz, Quad I/Q Demodulator and Phase Shifter; 16 phase select on each output (22.5°per step)
AD8332/4
Ultralow Noise VGAs with Preamplifier and Programmable RIN; Voltage noise = 0.74 nV/√Hz ; Current noise = 2.5 pA/√Hz
AD7980
AD9520/2
1Msps, 1.5LSB (24ppm), 92dB DR, 7.5mW pin-pin compatible with 18bits and higher sampling rate version, AD7982/3, etc.
12 LVDS/24 CMOS Output with Integrated 1.6 GHz VCO; On-chip VCO tunes 1.4 ~ 1.8 GHz; external 3.3/5 V; CO/VCXO to 2.4 GHz; 1 differential or 2 single; Accepts
16.67 MHz to 33.3 MHz crystal
ADP2114
Dual channel provides compact solution size; Optimized gate driving circuitry provides low system noise and easy power sequence control
ADP2323
High efficiency due to external low-side MOSFETs; Dual channel provides compact solution size; Parallel configuration provides higher output current capacity up to 6A
DSP
ADI’s Blackfin series DSP provides wide options for digital signal processing
What ADI Can Provide to Customers
Analog Front End (AFE)
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AD9271/2/3/6/7/8/9 evaluation board with schematic and PCB layout
Gerber file
High Speed FPGA-Based Data Capture Board (HSC-ADC-EVALCZ)
VisualAnalog™ software
AFE SPI Interface Software (SPI Controller)
AD927x Configuration Tool
ADIsimADC Modeling Tool
AD9278/9 BGA PCB Layout Gerber files
AD8331/32/34 evaluation board with schematic and PCB layout Gerber file
AD8333/39 evaluation board with schematic and PCB layout Gerber file
Clocking
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ADIsimCLK Modeling Tool
AD951x/952x evaluation software
and board
Power Management
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ADIsimPower
Evaluation board
DSP
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Evaluation board, emulation tools
More Healthcare Applications and Products information, please visit:
http: //healthcare.analog.com/en/imaging/ultrasound/segment/health.html
Sample Applications, please visit:
http://www.analog.com/sample
www.analog.com
Customer
Interaction Center
cic.asia@analog.com
Engineer Zone
http://ez.analog.com/
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