Practical application examples

TSA1204

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Practical application examples

9.1

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.

9.2

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 Figure 32 shows how a narrow input beam of acoustic energy

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

T/R

switches

TX beam

former

Processing

and display

RX beam

former

ADC

TGC amplifier

HV TX amps