tsa1204 STMicroelectronics, tsa1204 Datasheet - Page 24

• Manufacturer Part Number: tsa1204
• Description: Dual-channel, 12-bit, 20msps, 120mw A/d Converter
• Manufacturer: STMicroelectronics

Practical application examples
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9.2
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Practical application examples
Digital interface applications
The wide external buffer power supply range of the TSA1204 makes it a perfect choice for
plugging into 2.5 V or 3.3 V low voltage DSPs or digital interfaces.
Medical imaging application
Driven by the demand of the applications requiring nowadays either portability or ahigh
degree of parallelism (or both), this product satisfies the requirements of medical imaging
and telecom infrastructures.
The typical system diagram in
is sent into a living body via the transducer and how the energy reflected back is analyzed.
Figure 32. Medical imaging application
The transducer is a piezoelectric ceramic such as zirconium titanate. The whole array can
reach up to 512 channels. The TX beam former, amplified by the HV TX amps, delivers up to
100 V amplitude excitation pulses with phase and amplitude shifts. The mux and T/R switch
is a two-way input signal transmitter/output receiver.
To compensate for skin and tissues attenuation effects, the time gain compensation (TGC)
amplifier is an exponential amplifier that enables the amplification of low voltage signals to
the ADC input range. Differential output structure with low noise and very high linearity are
mandatory factors.
These applications need high speed, low power and high performance ADCs. 10-12 bit
resolution is necessary to lower the quantification noise. As multiple channels are used, a
dual converter is a must for room saving issues.
The input signal is in the range of 2 to 20 MHz (mainly 2 to 7 MHz) and the application uses
mostly a 4 over-sampling ratio for spurious free dynamic range (SFDR) optimization.
The next RX beam former and processing blocks enable the analysis of the output channels
versus the input beam.
Mux and
switches
Figure 32
T/R
HV TX amps
shows how a narrow input beam of acoustic energy
TGC amplifier
ADC
TX beam
former
and display
Processing
RX beam
former
TSA1204