AD9273BSVZ-40 Analog Devices Inc, AD9273BSVZ-40 Datasheet - Page 21

• Manufacturer Part Number: AD9273BSVZ-40
• Description: 12Bit 40 MSPS Octal ADC
• Manufacturer: Analog Devices Inc
• Type: Crosspoint Switchr

Specifications of AD9273BSVZ-40

• Resolution (bits): 12 b
• Sampling Rate (per Second): 40M
• Data Interface: Serial
• Voltage Supply Source: Single Supply
• Voltage - Supply: 1.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 100-TQFP Exposed Pad, 100-eTQFP, 100-HTQFP, 100-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

THEORY OF OPERATION
ULTRASOUND
The primary application for the AD9273 is medical ultrasound.
Figure 37 shows a simplified block diagram of an ultrasound
system. A critical function of an ultrasound system is the time
gain control (TGC) compensation for physiological signal
attenuation. Because the attenuation of ultrasound signals is
exponential with respect to distance (time), a linear-in-dB VGA
is the optimal solution.
Key requirements in an ultrasound signal chain are very low noise,
active input termination, fast overload recovery, low power, and
differential drive to an ADC. Because ultrasound machines use
beam-forming techniques requiring a large binary-weighted
number of channels (for example, 32 to 512 channels), using the
lowest power at the lowest possible noise is of chief importance.
Most modern machines use digital beam forming. In this
technique, the signal is converted to digital format immediately
TRANSDUCER
128, 256, ETC.,
ELEMENTS
ARRAY
BIDIRECTIONAL
CABLE
DEMUX
MUX/
HV
Tx HV AMPs
SWITCHES
Figure 37. Simplified Ultrasound System Block Diagram
T/R
Rev. B | Page 21 of 48
LNA
AD9273
BEAM FORMER
CW
CW (ANALOG)
Tx BEAM FORMER
OUTPUT
AUDIO
VGA
following the TGC amplifier, and then beam forming is
accomplished digitally.
The ADC resolution of 12 bits with up to 50 MSPS sampling
satisfies the requirements of both general-purpose and high-
end systems.
Power conservation and low cost are two of the most important
factors in low-end and portable ultrasound machines, and the
AD9273 is designed to meet these criteria.
For additional information regarding ultrasound systems, refer
to “How Ultrasound System Considerations Influence Front-End
Component Choice, ” Analog Dialogue, Volume 36, Number 3,
May–July 2002, and “The AD9271—A Revolutionary Solution
for Portable Ultrasound,” Analog Dialogue, Volume 41, Number 3,
July 2007.
AAF
PROCESSING
SPECTRAL
DOPPLER
ADC
MODE
CENTRAL CONTROL
PROCESSING
MULTICHANNELS
IMAGE AND
(B MODE)
BEAM-FORMER
Rx BEAM FORMER
(B AND F MODES)
MOTION
DISPLAY
DOPPLER (PW)
PROCESSING
(F MODE)
COLOR
AD9273